I have decided to heed advice and split my DS builds into different threads.

Here is an update on the T-72 just prior to painting. I did quite a bit more work and went further with photo-etch and other detailing than I originally intended.

Etch
I used almost all of the etch for the SBS turret.

I decided to redo the latches and strapping on both stowage boxes. Further etch was attached to periscopes, searchights and box supports. The trickiest job was the etch for the 125mm main gun. There were eight straps for the gun, a three part fume extractor and four vanes for the top of the barrel. The vanes were too thin and tiny to attach with super glue. When the vanes were carefully placed in the holes provided in the barrel, alignment was perfect and lateral stability was good. I decided to apply a drop of Future with a fine brush run along the length of each vane to run underneath by capillary effect. This glued the vanes almost invisibly and quite firmly to the metal barrel. The technique was useful enough to use on the barrel straps and box hinges as well to glue them more firmly and augment superglue.

Scratch building

I completed the smoke discharger harness on both sides with bent/looped wiring matching photos and did other details in styrene rod and solder wire.

I also found it necessary to improve the caps of each discharger tube. The caps have a distinct circular dimple in the middle not found in the Tamiya part. I decided to punch out each cap end in ultra thin styrene and create the dimple by embossing it with a finer punch. These were then glued to the ends of the tubes. Getting the dimples properly centered took a lot of trial and error and a lot of discarded circles but I achieved what I wanted in the end.

Tamiya

I spent a while cutting down the searchlight bracing for the Tamiya kit to get it mounted accurately on the SBS turret. Thank goodness for detailed Walk Around pics on-line.
I also compared a lot of photos to figure out how to mount the dazzler unique to the Iraqi T-72 which was only vaguely shown in the Tamiya instructions.

The profile in the Osprey book for the vehicle I am doing was particularly helpful.
I elected to use the Tamiya bracing for the snorkel wince the SBS etch was too weak and fiddly to hold it on. I am very impressed with Tamiya’s OOB details in the engine screening and flexible fuel tank pipes (not shown yet - will attach at the end).
Lastly, I am creating a cylinder to hold the turret for separate painting. I have had good luck with these in the past and I hope it will allow better airbrush coverage without needing to twist the entire model around so much. The resin turret and barrel are also ridiculously heavy so I will want them secured to the cylinder/pedestal to avoid dropping them while painting. I hope this isn't getting too boring but I can finally say it is ready for paint. I just have to pop off the wheels and turret and mount them for painting now.

Hi Colin @coling! This is a masterpiece indeed and it's a joy to read your progress. I loved the PE attaching with Future and I will definitely try it.
Waiting for your painting!

Thanks, Louis! I really appreciate your kind comments. I have to be in an extra-patient mood to start on photo-etch (best first thing in the morning after a cup of coffee). It still sticks to my fingers but I have a variety of methods to compensate. Using future as glue is a new thing for me but it is working well. The update below shows that it stands up to the blast of an airbrush when painting.

In answer to your question, I do not use a specific kind of primer for barrels and etch. I have done eight barrels so far with no problems as yet (could be famous last words). With acrylics, I find my layered approach of a black preshade, followed by various gradually lightening layers is tough enough not to chip of too easily. I will definitely avoid touching this T-72 barrel with all the delicate bits on it, so I hope it will be OK.

Thanks, Spiros. The PE/Future technique is a success so far. You can see below that it is tough enough to withstand painting.

Thanks, Erik. Great to have your encouragement. I have been painting the Firefly as well (I think you commented on that a while back on the armor group build). I had a mishap and dropped it while painting but I have since repaired it. Anyway, I'll save the commentary on that for the other GB.

The paint really makes the PE worth it!

Just a quick update on some techniques used for the next stages of the T-72 build. I hand-painted the rubber rims on the road wheels and decided to do the aftermarket single link tracks for Trumpeter. These required clean up on each link and 95 links each side - phew, a full day's work to assemble 190 links with care. I did these using the front idler and drive wheel plus two road wheels each side to get the exact shape for the track, including a tiny bit of sag over the top rollers (as per photos of the real thing) - pretty high track tension on the T-72, unlike the T-55 or T-62.

I used some bits of wood to force the track down around the rollers as the glue dried. After it was firmed up overnight, I removed the whole assembly on each side, including wheels, since nothing was glued to the suspension (just friction held inside with vinyl caps). I did this gradually so as not to break the track or suspension arms (the fit is pretty tight). I have done a first coat of flat black thus far. I am being careful to mark each track assembly so I know which side is which and what is front and back. I have had some bad experiences with confusing this in the past and distorting the track.

The next bit, which was a first for me, was the creation of stencils for the Arabic script slogan on the side skirts. In case you are curious, the Osprey source says that it means Asad Babil - "Lion of Babylon". I wanted to copy the artwork/script as accurately as possible , assuming the profile in the book is correct (no photo of the real vehicle, unfortunately). I considered doing this in white decal but was not confident it would work. I elected to draw and cut stencils.

The stencils will keep the artwork well-matched on both sides and also allowed some correction as I go along on the script (adding masking tape to adjust the shape of the letters). For the first side, all this took a few hours, going very slowly so as not slip with the knife and ruin my work. The letters are pretty tiny. BTW, I had a bit of a struggle to get the paper stencil to stick over the complex curves of the side skirt, which are accurately portrayed by Tamiya as wavy and curvy. I used tiny bits of double sided scotch tape under the stencil in key places to keep it pinned down - Tamiya tape covered the sticky scotch tape glue where if touched the model. After all the work on the stencil, I kind of dreaded the airbrushing, thinking that I could get nasty leakage under the paper and ruin everything, I misted on the flat white very carefully at low pressure and the results were good. Only a tiny bit of retouching will be necessary. What do you think?

Comments welcome.

Your tracks progress and "Lion of Babylon" stencilling processes are truly amazing, Colin! Thanks to your nice and essentially detailed pic coverage, they are fully understood by non-armor (so far...) guys like me. After I finish a couple of my ongoing aviation projects, I might try armor.
This T-72 looks superb, and I am waiting for your progress!

Excellent attention to detail Colin, the Arabic slogan is a nice touch and if so accurate. The casting on the turret is incredible. Your leveling technique for lack of a better term really shows the uneven wear in the paint. Nice approach on the tracks. I will take note of that. So far so good.

Here are a few pics of the completed T-72. The last fine painting to do included the starboard side stenciling and corrections to the calligraphy. Assembly of bits like the tow cables, engine screens, scratchbuilt front periscope, unditching beam, fuel lines and photo etch bits proceeded after major weathering to avoid damaging the parts or the finish.

. I completed weathering with Maru Technics Easy Mud in three tones (mid-east and North Africa Desert and Street Mud. . Much of this is invisible under the skirts but it works its way up on the front and rear plates and on the fenders. I don't have the energy at the moment to take more pics of the under sides but may add more later. I spent quite a while doing mud/dust application all around. Weathering took three days which allowed me to check the look of the slowly accumulating layers of mud dust and grime in different kinds of light. As seen so far, I also continued to weather by airbrushing different kinds of sand color first to get tonal variation and depth. I did this with the tracks a bit differently using Flat Black, Hull Red/NATO Brown and Flat Earth before applying Easy Mud and rubbed on graphite and Rub N Buff to highlight the metal segments. I did an oil wash on the hull and turret with various shades of black brown and tan and further work in pastels with raw umber. I next gradually laid down layers of CMK weathering powder in Sandy Dust and Dark Dust. I did several layers of Tamiya gloss to seal each application of pastels in before adding the next. The scorching for the exhaust is Tamiya Flat Black mixed with NATO brown. I also did a bit of rubbed-on charcoal to extend the blackening slightly. A final layer of dust was airbrushed on with very thinned out lightened Iraqi sand mix and a final coat of MM Acryl Flat, which brought the whole finish back to matt. So, that's it for this build. Please check out the final run of pics in the main section. Thanks for looking.