The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Third Series, Vol. 1, Part 2, Nos. 1&2, Periodicals, 1946-1947.
Later redrawn for the covers of Archie's Pals 'n' Gals #15, and Laugh Comics Digest #8
"Joe Higgins" lists the addresses of children who want to be pen-pals.
Story logo and dialogue spell L'il Jinx differently.