Well, I *thought* that the mailbox was fixed. After Sam and I managed to get it back on its post, I noticed earlier this week that the door was now detached on one side when opened, because the rivet that holds the door on had split into two pieces making it less than effective as a connector.
As it happens, I had already fixed the same problem on the *other* side of the door. Today, I finally had time to look in the Kitchen Junk Drawer (Thanks, Wulf!) where I found the little packet of screws and the little packet of nuts that I had used in the previous repair. I removed one of each from the packet, got a wire cutter to trim the ends of the rivet so it would come out of the slot, and -- after a bit of screwing around -- the door was securely attached again.
This is not a major thing, but I am happy to take such victories as are available for the taking. :)