HEMMTs are in the same MV collector class as armored vehicles......very expensive to own, operate, maintain and obtain.
Very few of them have gotten out the door in one piece.....most of the ones out there were built from salvage trucks unless they were prototype vehicles that escaped the torch.
I think Oshkosh did sell some to civilian or other government agencies mostly as fuel tankers or fire fighting vehicles. I could be wrong about that...could have been lateral transfer among agencies.
With an unlimited budget you can collect anything....most of us just have to be happy with the smaller stuff like deuces and 5 tons.
If it is just tech specs and information you want Google is your friend. All of that info is out there.
If faulty memory serves me we have a least two members that now have or have at one time owned a HEMMT. Lucky ^(*%$^%#'s.