The Bikes I Started with!!! There are quite a few Old SL125 also XL125 & XL175 here in Chiang Mai. They seem to be very Popular with the Thai's, The "Classic Bike" thing. Some are in Fantastic condition. There used to be a Perfect SL125 parked outside the UN Irish Pub most Days, not sure if it is still there as i hardly go into town. They have Classic Bike Clubs up here which would be a Good Source or else the Best way would be to come up here and just ask around the Thai Bike shops, i am sure you will find them, More here than anywhere else in Thailand. Good Luck.
Cheers Ian..... I would love to get the time to get up to Chiang Mai, I live in Jomtiem and take care of my 4 years old son so maybe when it's the school holidays I will pay a visit if I have not found one in the meantime. Also your Xr250 is a bargain, I have 3 of them that I rent out here and they are solid but you already know that. lol