I am trying to find a folding shift lever for a 1975 CR250M. The shift shaft is 12mm and the splines are at a 1.5mm pitch. I think it's the same as the 73-74 shafts. There are plenty of aftermarket levers available but none have any sizes referenced, they just state what bike they fit.
I'm sure that one of these levers has a 12 x 1.5mm cutout but without wandering around a motorcycle shop or parking area/pit with my vernier caliper I will never know which one might be suitable.
Of course when I ask the guy at my local bike shop he just rolls his eyes when I mention the age of the bike and doesn't seem to have the ability to think laterally.
Any suggestions would be greatly appreciated