http://books.google.com/books?id=RU8...um=9&ct=result
IRL this seems to say they were retired in 1993 along with the M151s. In an alternate timeline with an expansion of Guard and Reserve Units who knows.
IRL I have found several references to this being a hard vehicle to find so I am assuming they were not sold to the public in large numbers. Perhaps due to the fact that ear protection was required to drive them.