I'm curious about the Copal 0 shutter. I have a APO Symmar from the early 1990's that has an all-black Copal 0 with a 7-bladed iris. Did Copal go to a 5-bladed iris on newer shutters? If so, about when did this change take place?

Did earlier Copal 0 shutters (with the silver speed dial) have more iris blades than 7, similar to the Compur shutters of that time?