IIRC, this "magazine" was circulated to subscribers as a 5" reel to reel tape, with a bunch of mailing labels to send to next person. Unfortunately before the days of ubiquitous tape recorders, so it would be unlikely that many people dubbed copies for themselves.
You should also post this inquiry to Ballad list, assuming you
haven't already gotten access to the mother lode....
I would be very interested in seeing a list of contents, and
possibly interested in purchasing copies of some or all of the
recordings, if made available at a reasonable cost.
Wonder if CAMSCO would be interested ???
Best wishes, Thomas.