The foam turned into a full apartment complex is sending me. Like, they didn't just nest in there, they built a whole little neighborhood with rooms and everything? That's nuts. Nine years is a long time for those mice to get comfortable, so I bet that seat is soaked through with pee down into the foam, not just the cover. You can try scrubbing it with vinegar and baking soda and letting it bake in the sun for a few days, but once mouse pee soaks foam it pretty much never comes out. For 40 bucks in parts you got off easy on the engine, so maybe just eat the cost of a new seat and call it a win.

The plastic won because it's simple, not because old stuff was built better. Those fancy metal adapters had springs and tight clips that were made for a specific projector, so using them for scanning was always gonna be a pain. Sounds like the Brownie just happened to fit your setup, and a $6 holder that doesn't scratch your grandma's face is the right call every time.