That was one good thing about the pulps that has long gone missing, the cover art of semiclad girls. Sometimes in the grip of a lascivious alien, or lost on a hostile planet, etc. Then GGA (as it's known to the collectors) reached its peak in the lurid paperbacks of the 50s and 60s. Some of that art is very good. When I was looking at Silverberg a year or more ago, and found out about his Elliot/Beauchamp stuff, I saw how big a collectors' market there seems to be for paperback GGA. As I recall, "vintage sleaze" on ebay brings up tons of the old stuff.