There are some threads on this already, but I didn't find them. HSmith posted some good info on it.
You can cut a Wilson/Nowlin frame to fit a Clark/Para barrel.
You can cut a Clark/Para barrel to fit a Wilson/Nowlin frame.
I did the last. I took a Schuman barrel with a clark ramp and hand cut the ramp to fit a wilson frame.
It turned out great. Maybe I just got lucky. I mic'ed it, cut it down close and then finished it with files, stones and fine
sandpaper. I went very slowly and measured a lot. Having said that it took less than 2 hours.
You might pm hsmith. He'll know and he's a great guy.
Hope that helps.
9x