Yes that looks like a '71 CB750K1. Hope for the owner's sake that was a shadow, and not an oil leak...(Just trying to be positive). If that's oil spilling out he must be parked on top of a hill, judging by the way the oil streak is, and I'd guess the drive chain broke and got into the crankcase...
Spiros, can you please post a pic of the sprues with the seat, and the rear tail light pieces? The seats do have some external differences, and the rear tail light on the '72 - up models were larger and more rectangular.
Noticed that the pics you have showed the headlight ears (the parts that slide onto the forks that hold the headlight assembly) to be chrome plated, correct? This is just an observation, most of the books/restoration guides of '71's show painted ears, but some of the '71's I've seen did have the chrome ears (which were usually more identified with the '72-'76 K's).
If it's any help, think the colors varied depending on which country it was sent to. Most '71's I've seen were a candy apple red with gold stripes, or a medium brown color with gold stripes. With that being said, have seen a LOT of these bikes painted up with the silver, similar to what's on the box top (which would save some trouble trying to make gold colored stripe decals). Either way I'm sure it'll turn out great in your hands.
If anything I'm posting so much because now I want to find one of these kits to put in the stash!
