Lucky Coyne last appeared in Top-Notch Comics (MLJ, 1939 series) #1, which had contents packaged by Chesler.
Next appearance in CAPTAIN FLIGHT COMICS (Four Star Pub, 1944 series) #6.
Appears to be a rather blatant knock off of National / DC's "Calling All Cars" (later "Radio Squad") feature created by Siegel and Shuster, although the name of that verson's star is Sandy Kean. But the introductory blurb for this feature even describes Powers and O'Shay as members of "the famous radio squad."