I think all Rascal dropouts were the rear-facing horizontal kind that should work fine for SS/fixed gear use. They didn't switch to the funny rearward-semi-vertical dropouts until like 1995 or something. I have a Rascal that I use as a singlespeed and it works fine. The only thing is that the slot isn't as long as a true track dropout -- there's only about an inch of adjustment.
The only (easy) way to make a fixed gear out of a vertical-dropout frame is to use an eccentric hub. I think there's only one kind of eccentric hub out there -- White Industries makes it.
The only (easy) way to make a fixed gear out of a vertical-dropout frame is to use an eccentric hub. I think there's only one kind of eccentric hub out there -- White Industries makes it.