It's Robert Maguire, one of the best vintage paperback artists of that era. The artwork is a print of a David Goodis cover that he painted...it has a 400 signed limitation, but Maguire died shortly after the project was begun so only 12 or 15 of several different prints were released. Here it is:
maguire.jpg
Unfortunately, the dealer ended up passing on my trade offer a few minutes ago, so unless I make the trade even more painful (a higher-end (more rare) King, a rare Centipede title, etc.) it looks like the whole issue has been put to bed without a snack.
I actually have a vintage paperback (a Lionel White title) signed by Maguire on the title page, so will very likely let that suffice and keep my higher-end Kings and Centipedes...I was prepared to have the trade hurt, but not scar.
EDIT: I should add that along with the signed Maguire pb I also have a vintage paperback (a John D. MacDonald title) signed by Robert McGinnis (as well as the signed/limited/slipcased book that came out a few years ago) and a couple signed pamphlets/chapbooks/? (kind of hard to describe what they are) by James Avati. To my mind, these three artists make up the Holy Trinity of vintage paperback artists, so even if I don't manage to get my hands on that above limited print, I still feel pretty fortunate to have signed pieces by all three gentlemen.