When you think you have internet Painite, discover it's been online for years, but end up giving that news a free shrug and just posting it again anyway (I don't even remember where or when I first got this)...
http://www.mediafire.com/file/75286d7kmy90wfj/Unseen_Terror_-_Rehearsal_8-12-87.zip/file
Update from Mitch: "No idea who ripped it, but I
still have the original cassette here. It would have come from a trader
of mine from back in the day as the quality (like you say) is like first
generation."