I'm 'guessing' you would be close, if not in Miami to have been able to pick up such a machine, where it seems a few have found their way into the States.
I'm note entirely sure whether it was official importation from MZ or a large buyer in the US, but they all seem to be on the East coast, mainly in Florida. I would definately try to reach out to the Miami MZ club: Perhaps through this website-
http://mzpartsmiami.com/The US being a possible prospective market when MZ's were shipped to cuba (I seriously think there might be more MZ's in Cuba alone than in the whole of europe..) was short lived, as it seems only the 4 speed TS250's of year 1974 seem to be there offically, other than those that people have privately imported, perhaps even the later MZ's which were still distributed in Cuba until the curtain fell, I believe.
But after all that, it is only worth as much as people are prepared to pay for it. That means location, condition, financial climate, type of buyers, good advert/pictures etc.
But I would definately try MZ Miami club, if nothing else, they'll know a way to sell it, and to those people who would actually appreciate it too..