I'm not sure I can be much help on this one. It's true that before Joe Bethancourt passed he was an icon in the filk community (and hosted a highly regarded field guide to filk traditions on the Web), but that Web site evidently died with him (and its successor, as mentioned above, appears to have been infiltrated by questionable actors).

And unfortunately, my particular filk network is both in the wrong part of the country and just a little too young for its collective memory to yield a source-connection for this particular request. Worse, such online sources as I've been poking at have failed to produce clear answers as to the publisher of the album in question -- it doesn't seem to have been either of the nominally major filk producers from the relevant period.

I did come across a mention of Bethancourt's work having been featured on at least one episode of FilkCast; your best bet for tracking down the album might be to contact the producers of that show to see what information they have.