Here is the original black and white artwork for Marvel Treasury Edition #13 (1976) by Gil Kane (inked by either Romita or Sinnott or both). You can see the paste-up logos over the artwork. I did another post a year ago that featured Kane's sketch layout for this Giant Superhero Holiday Grab Bag. Nuff said!
Very cool! I don't think that I've ever seen the back cover artwork for this before. Gil Kane is the best comic book artist ever, imo.