I built me a fixie years ago using a 60s S&R. I really wanted to try it out, Often I would forget I couldn't coast and almost killed myself going downhill once. I think my big mistake was not having foot retention. I probably would've had an easier time and would've enjoyed it more. Fixie stuff was impossible without it. It was almost like relearning bikes, like the time I test rode a trike.

Sadly the bike was stolen before I could revisit the idea. Was one of my grannies old bikes too, real good condition for something that sat outside for years.