A real cleaning of a shutter involves removing it from the lens board. This allows for thorough cleaning and maintenance.
Typical removal ofthe lens blocks would involve simply unscrewing the front block en masse and the rear block masse. There is no breakdown of the front or back lens groups needed. Of course this doesn't mean that it didn't happen. Sometimes the front retaining ring, for example, is actually retaining the front lens element, not the front lens block.
I am not certain about your sample image above- so many sloping surfaces, hard to know what is what. this is where the infamous brick wall shows it usefulness. My first impression is that it doesn't have the curved focal plane of previous shots you showed?
My thinking is that whoever worked on the shutter removed it from the lens board. this means undoing the retaining ring/tube on the back of the lens, inside the film chamber. Underneath this ring is a washer that look amazingly like the one you show. I bet whoever put the camera back together forget where that washer went, or simply had it left over when he thought he was done. So he put it on the first place it fit- the back of the front lens group. The washer isn't serving any functional purpose on the back of the lens board, it's just your standard 'best practices' approach to tightening down assemblies.
Try for beter test shots. Try with and without the washer. Let's hope it was what I think, because you will be done shortly if so. But then again, other things such as people have mentioned might be the cause.
Oh, I haven't even given much attention to the back lens block. You can take a small screwdriver and very lightly see if it can be spun out by putting the screwdriver tip in one of the retaining ring slots. And see if it can be tightened down any. Be very very VERY VERY careful here- metal and glass are a nasty combination if you slip. There are other ways to check this- I save wooden chopsticks from takeout to whittle safer tools for things like this. All you are doing is checking for looseness.
Last edited by Dan Daniel; 05-02-2013 at 01:41 PM. Click to view previous post history.