Its a bit difficult to say what we are looking at here, can you give a bit more context? Is this the end off the shift plate? I think its a pivot or and end pin, but hard to tell with the photos shown.
It's the engine side of the lower shift cable. Even harder to tell without the pics. Maybe it's just my bad vision. I've seen video's replacing the cable and there are supposed to be set screws. If it's a pin I assume there is a way to remove it? No other way to pull the inner cable.
Going off this video, I would say, yes, those are mangled set screws.. https://youtu.be/PZN-HHuIDPI I did mine on my MC1 a few years back, but couldn't recall if it attaches the same. Hopefully one of the smarter guys on here will confirm, but I think you are correct.
Square headed set screws. They are supposed to stick out. The head is pretty much missing. Use vise grips or similar and unscrew them. The cable will come out.
Agree. That's an OLD cable. Those square-headed set screws haven't been mild steel (now stainless) for a very long time. If you're trying to remove the screws to get the cable out for replacement, just chop it and pull it out (with a draw cord attached )