Yeah there is a ton of stuff Lucas based the movie on. Even those old EC Comics by Al Williamson had some influence. And of course the King Comics Flash Gordon Al did along with Roy Krenkel.
It was a no brainer when Lucas asked Al Williamson to do the Star Wars Newspaper strips. They both were fans of old movies, movie serials and comics from the old days when they were in newspapers. Both were die hard Alex Raymond fans.