hi
the little 125 Sport from '75 seems to quite popular with quite a few chasing one. As Rob (MVista) found out, they are readily available (for a small production run Italian from the seventies) in Europe but, and here's the problem, it seems no one is willing to deal with overseas buyers.
Funnily enough, just as Rob was about to head overseas to collect his little gem, a 125 Sport was for sale on e-bay Australia for a buy now price of around $7,000 AUD and there was no bids .. ahh.
Anyhow, if ou are looking for one in the US the best bets are e-bay and michaels motorcycles
http://michaelsmotorcycles.com/ Micheal seems to get quite a few classic bikes through his shop including classic MVs