just bought a camera I once owned in the 70's

Welcome to APUG

I've never sold any of my cameras so I've never had the chance for a boomerang. It's amazing the OP had his come back home.
While not a sale, I did trade a Nikon F body even up for a refracting telescope in 1973 when Comet Kohoutek was coming into view. That got me started in astronomy so I guess it was a good deal. I replaced the F shortly after with another one which I still have and is still operational.