Ok, I see what you are seeing now and they probably are screw driver slots. But the latch/catch I was talking about keeps the pin from walking out. In your last picture the catch is right below the 2 o’clock slot notch. The worn screw, and hinge of the cylinder pin catch, is right at the bottom of your last picture. If you start to close the ejector rod crane slowly, you should see the catch start to retract. You will need to get it out of the way to try to unscrew the cylinder pin, when you do so.
That is how I see it as well. As it is right now the catch doesn't keep the pin from walking out. I'm not sure if it is worn or just installed improperly. I'll go to Ace Hardware tomorrow and see if I can't get an appropriately sized screw driver. I'll have to square it off with a grinder, but we'll see if I can budge it. It is soaking in Kroil now. Do no harm.