Lifetime of a Deuce, a very good question!
To what I know what the US Army did in Germany: They run the truck some 50000+ miles and than they go to depot maintanance, which means the trucks were completely disassembled, all groups completely rebuilt like engine, axeles, transmissions etc., frames and other stell parts sand blasted, primed, repainted (and during that more or less lost a good part of the readability of numbers punched into these parts).
Then the reassembled them in the so called "all new" state. The odometer after that was reading 0 miles.
On the seat base they affixed little triangle plates which documented the total rebuilt. However, these tags are part of the seat base and will most commonly say nothing about the other parts. The reassembly used just the parts available and NOT the original parts that belong to the frame. I know this for I once visited with the Escadron de Souvenier the depot in Savem, Lux, where they rebuilt the trucks (1984).
Engines are relatively easy to check, for they carry the tags of rebuilding on the engine. So you can say for shure about these engine, when they have been rebuilt the last time. If lucky, you find bearing and piston oversizes mentioned. Thats all.
For these trucks are babys of their time, the design engine livetime is probably limited to 5000 engine hours in hands of a carefull driver. Or some 250,000 miles, which is a lot for a truck designed in the early sixties and based on a design of the early fifties.
Wolf