Thanks Jim. That was the information that I needed, and right from the source too
What I thought was a rivet was actually the end of the switch shaft. Good thing I didn't start drilling on it! After removing the label, I saw the other two screws that hold the bottom plate in place. After removing those, the switch came apart easily. I did what you said, but also noticed that the number 4 leaf was not contacting the common contact in a parallel manner like the other three switch positions were doing, so I tweaked the leaf a bit to get it parallel. Then I made sure I had the same amount of leaf lift in number 4 as I was getting in position number 1. Switch went right back together and it's a good as new now.
Many thanks. Jim/ND6P