I am currently doing a Ghostbusters isolated score track for a Ghostbusters fan project here on the forum. This is my first one; the inferior separation on the 5.1 mix, the crappy edits, substitutions and tracked music made it a hard one to start with. I would like to do many others for myself in the future - starting with The Omen once I get my hands on the new R1 Special Edition. I'd also like to do the Halloween films as I have all the scores for those films on CD.
I must warn you though: make sure that if you are going to trade for promo/oop scores that the other party is giving you a direct copy of the original pressed CD/CD-R or is burning your disc from a CD image file/FLAC files on the computer. I have been ripped off many times by inexperienced traders who make copies of copies of copies of copies (there is degradation this way).