Oh for sure. I'd do something like that if I ever won enough money to leave work.
My stepdad has a customer who's really into old BMWs, restores them and sells them as a hobby. Small turnover etc but he just does it for the love really.
There's also a guy round the corner who goes to the US for a few weeks every so often, will fill a container full of old V8s, then drags some and others he builds up and sells. Had some awesome rat rods and stuff on the village over the years thanks to him. He's clearly big into that scene, dresses like he's out of Grease Lightning lol.