M38A1 questions

There is a M38A1 near me, it might...or might not...be worth a look.
So I have a couple of questions...
-It's been retrofitted with a Buick V-6. Is that easily undone? Are stock 4s available?
-The seller says it's a '64 (I understand that's late in the production run but the Marines bought some late ones..and it looks to be painted in USMC colors. Legit? I've read the USMC units had differences to Army trucks. If true, what are they?
-Aside from the obvious rust issues, anything to look for?I
The listing seems to suggest someone is selling it on behalf of a widow, so I doubt if there is much history or information to be had about the vehicle.

Thanks...

Definitely worth a look. Yes the '64's were USMC and had lockers supposedly. The V6 is easily undone and the setup with bellhousing adapter etc will be in demand by someone building a flat fender CJ. Plenty of F134 engines around still.
Edit: other USMC specific items are the "airlift" rear bumper.