Lynch
Here for the cookies and the tunes
I could be wrong, but dating back to the start of my DJ'ing days back in the 80's, these type of albums were usually promos given to radio stations for use on-air (not always, but much of the time). Some have different versions of songs, usually shorter and more radio friendly cuts. If that's the case, then you have copies that were rarely touched or owned by the general public.
(but again, I could be wrong).
Like LG said, catalog and list out everything before you do anything with them. Make the list detailed and go from there. You could have some really rare stuff or maybe not. I would say best to handle them as little as possible if you are planning on selling them. At least not until you get that list made. there are some vinyl experts around here that could offer better advice than I can offer.
Good luck.
