Yesterday I'd picked up a Zorki 4 at a thrift shop. The shutter button kept falling out and I figured it would be an easy fix. Upon opening the top of the camera, I'd discovered that the set screw had snapped. What was left of the set screw was just long enough for the rewind ring to work but not long enough to hold the shutter button/shaft in place. The photo shows where the set screw goes.

Does anyone have a spare set screw or where I can source one from? I'd checked with Yuri at Fedka and he does not have one. My last resort is to cut a brass rod and try using that in place of the set screw. The rewind cap would end up holding in place.