I recently got an MG34 parts kit and it came with this extra piece:
I appears to be an E6 Back Closing Screw. It threads in, but obviously is different than the one pictured in the parts IDs here (and the other one that came with my kit). Any ideas?
I've gotten around to inspecting this part closer and although the screw is original, the rest was added later. The main shaft is solid steel and is (was) locktighted to the screw via a allen-head machine screw. The other end (right as pictured) is tapped for another allen-head machine screw, which is shouldered at the threads and appears to be fabbed. The discs are stacked flat washers. I can't even speculate what someone had in mind when they made this. The shaft, although machined to match the step inside of the original screw, had another flat washer sandwiched between it and the closing screw. Apparently it was too short.