No US source for the Foster tape. Only him. I wasn't aware that he had a middle initial either.
Yes, he does give G. Pratt credit for writing "The Black Fox". I'd be interested to know if Pratt has a version out on CD. It's a good song and I'd like to hear others he has written.
Disagree that the songwriter's version is always superior. It may be here -- I've never heard Pratt's version so I can't comment. However, I've certainly heard people do versions of a song superior to that of the songwriter. For instance, I've always preferred Faron Young's version of Hello Walls to that of Willie Nelson.
I wasn't aware that there was a premium on thread space.