The transmission is s/n ZSA079719:
a) regarding the output shaft circlip usage, anyway to know its in there other than a disassembly? (no issues or symptoms and clean magnet plus yoke rotates smoothly with no sounds)
b) what is a reasonable input shaft "free play", with regard the torsion spring and ramps built into the front gear and such? (again no symptoms/ problems but roughly 80 degrees rotation noted to a feel of contact).
Technical detail not immediately found in the better known sites and expert documents, so help appreciated.