For example, Human Sexual Response is pretty well documented on the web, but the second album (In a Roman Mood), was never reissued on CD, even though one site on the web said it was "forthcoming."
Another album that was supposed to be reissued on CD was the Girls Reunion. There's a pretty good page about them here, where I learned, among other things, they traded drummers with Human Sexual Response (Malcolm Travis for Daved Hild). Robin Amos is in Cul de Sac now, and he looks considerably less glammy that in this picture (he's on the left).
Finally, back in the early 80s. Chuck Warner's Throbbing Lobster label committed a lot of good local rock to vinyl. Now, he's married to ex-Phoenix writer Sally Cragin and runs Hyped To Death, a label dedicated to remastering underground obscurities (mostly singles) from vinyl onto CD (or really, CD-R). While none of the Throbbing Lobster material has been reissued (apparently), there is a short history of the label here.