Those trucks are reportedly FMTV contract demonstration trucks. Basically prototype trucks from a manufacturer (I didn't read which one) that was not ultimately awarded the manufacturing contract. Note this is an older model with Michelin tires and door mounted markers. Likely a truck that was tested up against the S&S trucks for one of the manufacturing runs in the 90's.
As to them fitting a standard FMTV soft cab - I can't say for sure but I would guess they could be made to work. The A0/A1/A1R doors are interchangeable. PS Magazine has articles listing NSN's for door assemblies and makes note of the fact that A0 and A1 doors were no longer being supplied and that all orders for replacement door assemblies would receive A1R type doors regardless of truck serial number...... though I'm not sure what unit is ordering them at ~$8,000 per door assembly.....
I would caution that anything sourced from some Euro model might be very difficult to find parts for such as glass, window regulators, etc. It also might be that parts are easier to find. But all of this stuff is approaching 30 years old and likely no longer manufactured so.......
The door handle looks like some 90's VW Jetta plastic garbage. But admittedly it is tough to tell from a grainy photo taken from orbit.
