Chosen Solution
I recently got a Power Mac G5 for $20 (pretty good deal). However, the latch on the back of the Mac that unlocks the side panel has fallen off, and the seller said he lost the screws for it. How can I put it back in its place, and where can I get the required screws?
Someone managed to snap off the screw heads which holds the latch. Your image is a bit hard to see things clearly, it’s also possible you are just missing the screws. I’ve see this a few times in the Mac Pro systems as well.
Here’s what it should look like
Often I find these have a thread sealer on them so its not easy to get the threaded piece out. See if you can apply a dremel tool with a very small and thin cutter to cut in a slot into the screw. The other option is getting a left hand drill to ease out the core via drilling in the middle the drill might catch and unscrew the core. Finding a replacement latch will take some doing and you’ll still need to find the needed flathead screws that hold it on. I found this one listed which is the complete setup: PowerMac G5 Case Latch Lever + Lock
@sheepshaver all you have to do is to place this
back onto the handle
and use two short metric thread screws to reattach it. From your images, the thread is existing and there are no broken screws etc. in it. Take the handle to any decent hardware or automotive store and try the screws out. It looks somewhere in the M3 to M4 range.