I'm going to get on my righteous horse right now, and say you all need to check out this site I just found:
http://old-school-hiphop-tapes.blogspot.ca/
This guy uploads old Hip Hop radio from WBLS and other stations. He has Mr. Magic, DJ Red Alert, Marley Marl, and others. He ripped all of these to digital audio from tapes he made back in the day.
Unbelievable. I'm in heaven listening to this right now.