"What Are These Heavy Metal Objects I Found In A Thrift Store?"
Answer: "You hang weights on chains to power mechanical cuckoo clocks. One powers the clock mechanism, and the other powers the cuckoo. The weight turns gears in the mechanism as the chain drops. To wind the clock, you pull on the other end of the chain and bring the weight back up, and the same for the chain that powers the cuckoo."
Cabbage sliced for making sauerkraut.
5¼"disks came with stickers to cover up the notch to make them read/only again.
So the thing in not for write-protecting; quite the opposite actually.
Second this. Notch = writable, no notch (stick some tape or the like over it), write protected. If you wanted to use the back side of a single sided disk you had to punch three holes in the plastic housing, the write protect notch and two that would line up with the hole that marked the start of the track. We usually made a cardboard model of a disk to guide the punches as it required a fair degree of precision.
Single-side floppies were far cheaper than dual side, but at least by the time I was on the scene the chances of a failure on the back side were very low. I would guess we lost more due to not being careful enough when punching the sync holes than were bad from the factory. (One jaw of your punch had to go inside the housing and the disk was easy to scratch.)
I think you mean seat covers not toilet paper