The problem with most cotters from the bike boom era was that they were soft and came loose from normal peddling. WE had several VAR # 07 cotter presses at out shop but sometimes a week later a customer would come back with loose cranks!
Add to that, French, British and Italian sizes plus oddballs in between. We had a VAR # 371 "cotter vise" to hold the cotter while re-filing the taper.
>http://www.sheldonbrown.com/var/pages/var0012.html<
Zeus made some hardened steel cotters which fit most French cranks. They were expensive and in short supply but they never came loose.
Chas. Colerich
Oakland, CA USA