I use to had a small board like that before I cleaned my garage that we called "the Wall of Fail" that held all of the broken tools, broken car parks, and jerry rigs that the previous owners of our cars did. I had an oil pump drive shaft that looked like a drill bit, pieces of old valve seals that ended up in the oil pan (Ford special?), a spark plug that left it's ceramic housing in the block, a couple of cheap ratchets that came apart, a socket that somehow bent, and the chopped piece of electrical extension cord that a PO used for the ignition wiring. I still have most of the bits but took down the board because I needed the wall space. Always good for a laugh.
We have open rafters in the garage so that wouldn't work. I need to do a good cleaning of the garage again soon since I seem to be losing more and more tools lately. When I finish I might put the board up now that we have a new car (the Dart) to add more things to it.
I was able to get the rest of the plug out of the block. It really was funny to pull just the metal bits out. It was during a time when we were adding things to the board almost daily because of all of the stupid things that the PO had done to it. Started out as a good laugh but by the time I pulled the oil pump drive shaft that looked like a drill bit, which was left in the oil pan by the PO after installing a new one, it became less funny and more annoying.