1. Bob Kane (Verified by Schwartz at Kansas City Comic Book convention in 1992. Covers and stories were shown to Schwartz, along with tons of other art credited to Schwartz, and Lew went through each one and verified what he did and what Kane did. Lew specifically stated, that, on MOST of the Batman stories, he was told by Kane to very lightly sketch in or pencil the Batman and Robin figures, then send the art to Kane for finishing off before being submitted to the inker. For this particular cover and story, Schwartz categorically stated that he had NOTHING to do with this cover or the accompanying story.)
2. Lew Sayre Schwartz (stated by Les Daniels in the book "Sixty Years of the World's Favorite Comic Book Heroes"). Lew Sayre Schwartz himself denies pencilling this so this tips the scale towards Kane pencils.
Inker credit verified by Charles Paris.