The 6 speed Shimano 600 freewheel from the early 80's has twist teeth and is pretty awesome in my experience. I've had a couple but nothing smaller than a 28 tooth.
A Suntour 6 speed freewheel (non ultra) will index with Shimano 6 speed gears and shifters. Don't rule it out.
Last edited by clubman; 04-18-22 at 03:19 PM.