Cheapest entry fee:

https://us.armscor.com/products/gi-standard-fs-38-super-1

I bought a Rock Island Standard FS, with comabat sights, full length rod guide, and ambi safety, in 9mm, and my Colt 38 Super and 9x23 barrels fit and functioned w/o a hitch on that 9mm frame.

I've since sold the original Colt w/ that 9x23 barrel, but kept the Super barrel. I worked with HS-6 and 124 Remingtons that I went to 1400, but came back down and run them at 1300 even.