Quote Originally Posted by Klainmeister View Post
Nothing, actually. There's no open shutter function nor is there a spot to thread on a shutter release (for a press camera or something?). Therefore the solution we came up with in HS was to glue onto the lensboard a threaded shutter release adapter that hits the shutter arm. Effectively, we thread a locking cable release into that adapter, @#!*% the shutter, open and lock it. Kinda ghetto, but it has worked for about 8 years or so. Now that the new camera doesn't take the same lensboard, I realized I won't be able to use the same technique, unless of course I want to glue it on that one as well.
I have the same shutter, it has a button that you push toward the rear of the shutter to hold it open, to focus. The button is about midway along the slot the cocking lever moves in. I found it more convenient to use "B" and a locking release as mine is on a recessed board.
No cable release socket? It must have been broken off or removed, this can be replaced. The 90mm Super Angulon is not a lens for press cameras!

To replace the shutter, you will have to match the threads and the spacing within a very very small tolerance. New shutter are almost unavailable, so the only source is cannibalising other lenses with all that entails - accurate measuring, CLA for the 'new" 40 year old shutter, aperture scales, etc.

A Copal "O" will have the same dimensions as a Compur "O", and so on.