Ok, guys. Tech support at Para USA says the only thing holding the slide stop lever is the plunger and spring adn that their is no divit in the slide stop. Their is a divit in the thumb safety but we knew that. I asked if the bbl link could be worn or streached. He said it could be but that would not cause this. That would lead to poor timeing, lock up of slide to frame and accuracy. He said to first change the lever, then the plunger and spring if the new lever did not fix it. If the new plunger and spring don't do the trick, it will have to go to Para for a new plunger tube. Paras are not staked in, they are part of the frame.
Actually....with the 1911 completely assembled correctly, the slide itself holds the stop in because the part of the stop (arrow in my previous post's photo) is captured behind the inside of the slide face. That is why it must line up with the notch for take-down. It shouldn't come out, even if the plunger and spring are missing, unless the take-down notch is lined up.
Unless I'm missing something, the only way a lever can come out is for the top of the slide stop to be worn enough to slip under the bottom of the slide or the bottom of the slide has to be worn...or the slide to frame fit is loose enough to allow it to slip out without binding the slide.......or just by a freak of timing and slide cycle speed it is popping out at the notch (hard to see happening under normal slide speeds, but I've seen strange things before).
With the slide on the frame, can the slide be wiggled upwards?.....Or rocked side to side?
With the gun assembled with the old stop in place....move the slide back and forth in different locations (other than lined up with the slot) and see if it will push out with finger pressure. That will tell you exactly what/where the problem is.
My curiosity abounds here.