Jason Cosmo - Combine?

[This Is Not The Michael You're Looking For]

Ok, so this one is a little weird. Back in the late 80's/early 90's Dan McGirt wrote a three book fantasy parody series (meant to be longer, but the publisher bailed) about a hero named Jason Cosmo. The books are called Jason Cosmo, Royal Chaos, and Dirty Work. Fast forward 20 years later. Dan McGirt is now rebooting the series (his words...he's also referred to it as "digitally remastered" revisions), essentially telling the same story but rewriting the books. The first of these Hero Wanted has the same basic plot and characters as the first book of the original series...so...

Should these be combined into a single work or left separate? Opinions? Has anyone actually read both (I've only read the new one) to make an informed judgement about how much these are rewritten? We can certainly ask the author (who is occasionally active on GoodReads), but I've found that author opinion doesn't always match GoodReads policy so I wanted to get a feel from the librarian group on this one.