When I said "it was bought in an auction" it doesn't mean it was me. I was able to talkt this morning the first owner, a very kind gentleman.
The bike was bought by a scrapyard owner in an auction in a full lot. The man I spoke to this morning bought it from the scrapyard owner, and scavenged the rest of the bikes looking for the best parts. He restored the bike himself, painting the parts with an air compressor -not a pro work but pretty decent except for some visible "dropping"-, and rebuilt the engine. We are talking 1998, that is, the bike rested in the scrapyard for more than 15 years after his comission out of service.
He had a lot of trouble getting the paperwork done. After that, he used it for about one year and sold it to the guy I've bought it from. This "first" owner told me he rebuilt the bike with new piston, rings and bearings, but had to sell the bike because he had a back injury and couldn't ride, and after all his work he was spending more time cleaning the bike than riding it.
The guy I bought the bike from used it only one year, and in 2000 he put it to rest until the day before yesterday. It has a great, loud sound, some kind of "single Harley". The children were looking astonished as we started it. I'm a little dissapointed because it drops more oil than I expected, so I guess I will have to replace some seals. I will not rebuild it but I will have to "wrench" a little, when I tought it was "ready to run".