It's a shame you don't turn some sort of profit. The public at large assume four strokes are where it's at.
It's nice to give a second life to these discarded/ abandoned beasts with plenty more to give, but how many of the new owners will wreck them through abuse or straight petrol, or just give up because of a minor problem that is readily overcome?
It's good you gain satisfaction out of it. Many people don't get that out of their jobs.