I'm considering converting an old frame I have from being a single-speed to an internal-gear bike. Problem is, though, that ALL internal gear hubs seem to be for 135mm dropout frames. What I have is an old Panasonic touring frame with Tange tubing (butted in the main triangle, straight tube on the stays if I am correct) which has previously been set to 126mm. Since the frame was a cast-off I collected when my trashy neighbors got evicted and all their stuff was put to the curb, I remember that the frame wasn't straight when I snatched it off the street and had my local mechanic cold-set it to 126mm (it may have already been a 126mm frame for all I know).

So, is it advisable to cold-set a 126mm frame to 135mm? What about a 120mm frame? Or, maybe I should be asking if anybody makes an internal gear hub in 126mm spacing?