Has anyone tried fitting the 127mm and 135mm Raptars into the same Rapax shutter.

Just wondering if the threads on the 127mm and 135mm cells are the same diameter or different.

I have a Rapax shutter for a 135mm f4.7 Raptar that isn't exactly "jammed", but won't cock...feels like something is in he way of the cocking lever. If I can't fix it, I may be looking for a replacement shutter.
Bob.