The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Part 2, Periodicals, 1941, New Series, Vol. 36, No. 3.
The King signature is found in many features credited to Warren King by Jerry Bails' Who's Who, so it can't be Robin King.
Signed in splash panel.
The wedge-shaped faces with eyes far apart and a little out of line point to Reinman.