In Houston they would hand-sand a car to the bare metal for $25 and a really big bottle of rum...
That was in the early 80s though.
Hand sanding cars to prep for painting? Man, that brings back a few memories.
Back in the 90s an ole school buddy of mine decided to resurrect his Dad and Grandpa's old restoration business. We worked for and with each other intermittently for about a year trying to rake in the dough. My animal (horse and dog breeding) and his auto-restoration. He loved stripping the cars down to bare metal, removing lights, bumpers, interior, etc. Then baking the paint. He wet sanded the entire body by hand. The guy had a fucking old-school gift for body work like no one I ever seen. He even knew how to re-chrome older cars.
We restored his family's singular huge auto-bay that had been unused since the 70s and was specifically built to bake-paint cars. Our first car together was a '71 Chevy Caprice. We spent 3 days stripping, wet sanding by hand, then prepping it even more while it was on blocks. My hands were like prunes, my muscles ached, and I was already accustomed to hard labor. When were done with the paint, then clear coat, that car was the most beautiful thing I ever seen. Then we had to put everything back on it, which took another 2 days.
We did make a nice chuck of change, but after figuring the hours spent on it, I decided it was too much labor and time to continue doing it. We did another car and and old truck together, but by then I decided I didn't want any part of that shit. It's something one really has to have a passion for and not many people these days can afford to have it done that way.