The on-sale date is the publication date reported in U. S. Copyright Office filings and Comic Reader #136.
Disputed credits. Both Saltarella and Jim Van Dore think that Ernie Chan worked on this cover. Saltarella thinks Oksner pencils with Chan inks. Van Dore thinks Chan pencils with Oksner inks. The Comic Reader #136 has Oksner on both pencils and inks.
Colors credit provided by Anthony Tollin.