Re: Three worksman frames :)
Not sandpaper. I use a drill with a wire wheel. I like the brass wire wheels better than the steel ones. Use eye protection. Chemical stripper can remove a lot quickly which you can scraped off with a putty knife, then use the wire wheel. If you have a side grinder, a wire wheel in that is supposed to work nicely and pretty fast. I don't have one, so can't really say. I've stripped a Worksman down this way with a drill, a couple vintage Schwinns and my 39 Elgin. Takes a while, especially if you're also doing a chain guard and fenders, but just a frame and front fork aren't too bad. A few hours, especially if you use stripper first to remove much of the paint. Stripper is nasty stuff. I've had good luck with the walmart variety, better than zip strip and less expensive. There is another kind much recommended and sold in automotive outlets that is for aircraft. I haven't tried that kind and can't say from personal experience. I tried using sandpaper on my first strip down, did another just with the wire wheel and now first use stripper and follow it up with the wire wheel. Protect your eyes! Bits of wire come off the wheel. Good luck and nice score on the bikes.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...