Jerry, I'm not sure if it relates to what youre chasing, but I bought a pipe to suit my Mk7 off Donny Newell years ago and I think he said it was a Circle F. It comes in two pieces, it has the short 90 degree exhaust header section, which slips into another 90 degree bend beginning of the rest of the pipe. Havent got to use it yet, but word is they were a little topend pipey.
Mike