This cover, which is actually the splash page in the origin story of Doctor Strange that appears in this issue, was also used (sans Strange Tales logo) for the cover of the Marvel Masterworks: Doctor Strange Vol. 1 and the Marvel Milestone Edition: Strange Tales comic (which is actually quite rare).
INSIDE FRONT COVER
Inside front cover: A great Terry Beatty cover from The Comics Buyers Guide #402 (July 31, 1981).
INSIDE BACK COVER
Inside back cover: This is the cover to the comic fanzine Rocketblast Comic Collector #80.
I always use the original back cover on the customs.