FMC/M113
I've seen post on here before about the FMC and how hard it is to find parts; I don't remember anyone looking at the vehicle as a M113, or M11 variant.
In another life I was a Track Vehicle Mechanic, in the 1970's and 1980's; for Uncle Sam. Many of us grew up around M113's
http://www.army-technology.com/projects/m113-armoured-personnel-carrier/
I posted a link to the link between the FMC and M113 family of tracked vehicles; good reading if you were never in the Military, or around the M113 family.
The FMC in the ops first pic has full metal tracks; most of the M113 family had rubber cushion that bolted to each track pad; to enable the vehicle to run on paved roads. And believe me the M113 was a fast vehicle, for it's size, on highways.
FMC had the contract to build the M113 family. So Uncle Sam paid for the design work and testing. So why not make a few vehicles for special civilian purpose.
MAINTENANCE: Oh Yes, they do need a lot of maintenance; probably prohibitive in the civilian world. In the Military; it was just figured in.
I am not around them now; but they made LOTS of them, and spare parts. So maybe through Military surplus channels, there had to be parts around.
From what I gather, the bodies would be different, but the drive-line for the most part would be the same.
The M113 Personnel Carrier was phased out by the Bradley and later by the Striker., which was wheeled.
Honestly we had most work ; on the electrical, hydraulic, track, and armament systems. The Detroit V-6 was bullet proof, as was the transmission. Oh sure we put on a lot of filters, turbo's, and track parts. I don't know if in a commercial setting, you could make money with one, with maintenance costs.
In my sleep I can still hear the M113 screaming down a trail.
old1