Sorry about resurrecting a dead thread. Did you end up buying it? I picked one up and restored it and it's a fun little bike. FWIW, I hit 62 mph with mine on a recent Moto Giro which I don't think is unreasonable for a 125. I wouldn't want to run it up there all day, but it will do it if pushed.
Here is the restored end result at the Giro..