That makes sense, that it might be designed for 620. The previous owner seems to have put a couple of thin card spacers between the reel and the spring-loaded clips that hold it, so that'd make sense. It does seem to ease a bit once started. I opened the back a fraction just to ease the take-up reel away from the base and then wound it on to frame 2. I'm fairly sure that's done it. Shame if I need to lose that first frame, though.

The scan would be nice, thanks!

This one is a 6x9 KW Patent Etui. It has the 105mm 4.5 Tessar lens, and the longer bellows, so it'll close-focus down to a couple of centimetres. It also has rise and fall. I've not had a chance to develop any film yet, but the shutter speeds seem very good, even the 1 sec speed seems close enough to me. I can't spot any light leaks, although the developed film will be the test.