Originally posted by Ex Finn. I would remove the plate (those are Philips head screws right?) and see if there is a way to put a friction device or brake on the pinion shaft.
Should not be too involved.
Yep, I want to see what's inside that black box and, yes, those are Phillips heads. It's the kind of simple-
looking operation I've proven so adept at bungling beyond the point of restoration. I'm going to get help with that--it's too valuable a lens.
Originally posted by Ex Finn. The thumb screw looks like it could be a collar lockscrew. for loosening and adjusting camera horizontal or vertical after mounting to lens.
Yes, that's it--very useful. Thanks!