My mother's old school car that I restored with DuPont lifetime clear coat (the factory paint was lacquer back then) has a fuel sending unit in the tank that can not be found.
If you are ever at a U Pull A Part and see a Chevy Malibu Wagon, snag me one. I need the fuel tank sending unit to make her gas gauge accurate.
On a related note, a large U Pull a Part, that started as Auto Acres in Milan, IL, a huge well known salvage yard has closed. My mom's brother was one of the guys that ran the place for about 40 years and was also the used car manager there. I used to go to work with my Uncle on Saturdays, they had a party line and I would sit there and listen in on the phone. I would also wait on customers, I was like 7 years old then! My dad worked there when he was young, changing out motors for mechanical customers, he could do two a day. My father was one hell of a mechanic. When he retired he was maintaining a fleet of several hundred semi tractors. Damn do I miss him.
Cheap aftermarket parts have put a lot of salvage yards out of business. Did I mention my grandparents also owned one? Today's EPA regulations would of never permitted them to be in business today. I remember when people would call for used alternators and starters. They had a darn good business for many years and it helped supplement my Grandfather's WWII VA (Navy) benefits, as he had arthritis so bad he had huge knots on his hands and elbows preventing him from doing so much.
I can still "smell" that VA hospital/clinic in Iowa City.