G'day Eric (@eb801),
The books don't have any info on SF-Z but there is a profile of SF-R/JP504 and two pictures of it (one with SF-S/MN134 in the background) taken at B78 Eindhoven. These show the full 8 rocket load.
What is interesting about your photo above, is that SF-Z has, on that occasion a long-range configuration of a drop tank (inner) and two rockets (outer) per wing.
The inner rocket rail could easily be removed and a drop dank rack attached in their place, so your 8 rocket configuration is still valid.
SF-R retains the lower D-Day stripes, but the white is all but gone on the fuselage, while SF-S still has black and white under the fuselage.
SF-Z clearly does not have D-day stripes on the undercarriage covers, nor do they seem to be showing under the wing, so it is a good bet that it didn't have them. The fuselage underside is too dark to tell.
That may mean that it was a replacement aircraft, post D-day, and that might indicate that, in spite of the early serial number, it was an upgraded airframe. Certainly, the tailplane looks to be the larger Tempest one judging by the proximity of rear fuselage band.
Judging by the angle of the shadow, it probably has a 4-blade prop, too.
I must say, again, that your build looks great.
This whole build blog has re-energised me to pull my Typhoons out again as soon as I have my current builds out of the way.
I can't wait to se your end result.