APC's and M548 (cargo version)are regularly sold through dealers in the US, if you read the MVPA magazine there is a company in New Mexico that has M548's for sale ($31,000), a dealer in Idaho recently sold am M548 to a private individual as well they sell them to companies. The M113 is a different case because they are still being used by the military. In Canada they have gone through many upgrades ie streched bodies, external fuel tanks etc the latest thing I have seen is rubber tracks, Yea rubber!! really neat less noise,vibrations and anyone who has ever changed an APC track this is a piece of cake. The M113 was built in the early 60's and is still used by many militaries all over the world. This is still an excellent piece of kit made in the US.
I would dearly love to find a Cdn Lynx APC to restore, if anyone has one send me a message, APCs are like hen's teeth impossible to find