As many have said, occasionally the ammo gods smile. Over the years I have been setting aside some ammo for the “just in case” possibilities. One weekend a lady at my church asked me if I could help her move some junk out of her garage. Mostly it was old yard tools, rusty mower, broken stuff. We uncovered an ancient aluminum ice chest. Thinking it would be light, I was surprised when it wouldn’t move. When I opened it, the smell made my eyes burn. It was FULL of colorful boxes and metal tins of .22s. From the boxes and brands, they were mostly from the 50s. Copper shells, not brass. She said those were left over when her husband closed his hardware store in 1965. She said if I could use them, take them. I did. Some friends that collect such things as old cartridge boxes were quite happy to accept almost untouched, full boxes, and some excellent trades were made. I might have put a few aside for just in case, too. They still shoot mighty fine.
What a score on your part! I’ve shot a lot of old .22s that had oxidized lead bullets on them...not a problem to shoot.