From what i know there can't be many in the 'states'. In fact not that many 2 stroke MV's at all!
I have a friend who is selling a restored 52' one in the the UK but i doubt you want to go to all the bother of importing one.
I might also be thinking of letting my own unrestored 125 2T 4V go, but you guys over there tend to like the restored bikes from what i gather and mine is certainly as unrestored as they come
Goo luck with your search.