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.
The "Red Kamphor" on the cover doesn't really resemble the character inside the comic.
The crooks' car--which they force Ernie to drive--has right-hand drive, which is not typical for autos in the USA.
Most Roscoe one-pagers weren't signed but they appear to have been done by same artist, who did sign a few of them "Baldwin."