At some point, the original cylinder in my '79 Catalina was removed so the latch can be moved with a flathead screwdriver, I'm guessing whoever did this drilled the lock out and pried it out piece by piece, as the faceplate for the lock base is partly broken . The new lock doesn't drop down in the hole in the piece, so I'm going to need to remove the lock trim. The lock's swivel cover was removed, but the base is held on the trunk lid by a pair of 5/32" rivets. I found the cover in the trunk.
I'm going to remove the latch mechanism from inside the trunk lid and drill out the two rivets so I can insert the new cylinder, then place the swivel over it. Does anybody have any suggestions on how to reattach a previously riveted part this small? I was thinking some kind of glue might work, or possibly a pair of similar sized screws, but I'm not sure.
Like doc mentioned, pop rivet guns are very inexpensive. They're handy tools in general. I've used mine lots in various places across my vehicle for fabrication & repairs. As you say, machine screws + nuts can work too, if there's space.
Get a pop rivet gun kit? This is just a guess because you didn't provide any pictures of what you're trying to accomplish.
I'll put some up in a little bit. I didn't think about that. Haha.
I installed the new lock into my trunk today and repaired the emblem cover. When I drilled the rivets out, the faceplate came off and a good-sized spring shot off the trunk lid. Luckily it hit the garage door and rolled back to my feet. I figured out how the spring held the emblem itself on the mount and reattached it. The emblem had been laying in the trunk for over 10 years. I'm not sure how whoever broke that thing off actually got it off, it's pretty well on there. I used 1" long #8 machine screws to hold the cover over the new lock. It was tight in there behind the latch, so I used an 11/32" deep socket to hold the nut in place and twisted the philips head with a screwdriver until it got tight. It opens and closes without a screwdriver again, and there's no gaping hole in my trunk lid. The new lock retainer from GM is crap, it doesn't match what was in the car at all. I reused the one that came in the car instead.
Here's a picture of the base for the swivel cover that I'll be removing and replacing. The service manual diagram for the installation is in the other image. It doesn't specifically address the rivets, only the installation of the lock cylinder. The manual describes the rivets in the preceding section. The two rivets are on the left and right sides of the silver bracket.