They’re from the phones you see in old movies that you had to crank to talk to an operator, commonly used up until the 1950’s. I put my multimeter on one and it’s still reading 1.3 volts. The owner told me I can take the whole lot of them if I want them which I’m tempted to do just because I like to collect old junk but I probably drag enough useless crap home as it is.
Only one way to find out… I’m going back on Friday to snag the rest of them so if any vital services go down, it might be me.