I'm curious about the blade thickness too. Is the thinner blade the Craftsman?
Regarding the other variations, the knife on top appears to have been heavily reworked so any blade length measurements are inaccurate. Sadly, it looks as if someone reground the blade edge, ground the entire blade face, and then buffed the heck out of it. Personally, if I were to pick one of the above to customize with stag handles, this one would be my last choice. The abused blade just isn't worth it. IMO, of course.
The center knife could be in original condition. My unused 15OT has very light striations from the factory running lengthwise down the blade as well. The light reflecting in the photo may be exaggerating those striations. I'd pick this one for a custom handle; the blade is in excellent shape, but the handle has minor problems.
The lower (Craftsman) knife has the original (although worn) finish as evident by the blade etch.
Just an FYI, the knife is a 15OT. As in Old Timer model 15. Getting that correct will help with your internet and forum searches. :thumbup: