I tried again with Dolly, and this time I didn’t lose the film. Partway through the roll I realized the shutter has a cable release socket, so I attached one and alleviated the problem with the odd release action.
The results were disappointing. This is my first experience with Efke R100, and I blame myself. The images were overexposed and very grainy. The exposure may be my fault or may be a sticky shutter; the grain is probably due to my developing process. I used my default Rodinal 1+100 stand development. Next time I will try something more conventional.
A few of the images were more exposed on one side that the other. Perhaps it is a sticky shutter and not my eyes.