I didn't fix my shutter in the end, I bought another one... which also had issues (which were known before I got it). After a clean and lubrication, it worked... for a while, after which it needed to be done again... and again... and again!
So I have decided to abandon this one and look for yet another shutter.
Yesterday, a friend at work returned a Flexaret TLR which I had loaned him a few years ago. The shutter (a Prontor) was slow to open and close so I took out the cells, cleaned up the blades and got it working again.
In doing so, I wondered about the thread size and tried the Super Angulon cells which fitted!... Except that the overall length from front to back was about 2.5mm too long.
Eventually I realised that the front is threaded all the way up to the edge on the Prontor, whereas on the Synchro Compur, the thread starts a few mm into the barrel with a slightly wider opening at the edge. There is a corrosponding shoulder on the back of the front cell which fits into this. However, on the Prontor, the shoulder prevents the cell from screwing in all the way so despite the shutter data showing an overall thickness of 16mm for both shutters, they might not always be compatible.
After a bit of thought, I decided to file down this shoulder (please don't judge me - the lens isn't in pristine condition so I'm not destroying anything valuable). I bartially screewed the cell back into the old shutter to serve two purposes. To protect the end of the lens from swarf and to provide a channel just the right widthto work as a guide for a thin file.
The result is that the front cell now fits fully into the front of the shutter and I am 99% that the spacing is now correct.
Anyway, the point of all this rambling is to ask a favour:
If anyone has a 65mm Super angulon in a Synchro Compur shutter, I would appreciate it if you could measure the overall distance from front to back (of the metal outer casings).