All I can tell you is that Gabby Scoops appeared in issues 25-40 of Crackajack Funnies.
Crackajack Funnies. -- Poughkeepsie, N.Y. : Whitman, 1938-1942. -- Published no. 1 (June
1938) - no. 43 (Jan. 1942)
Index to Comic Art Collection: "Crab" to "Cracked"
I don't know what you have, but I'm sure it's a rare piece of golden age comic book ephemera. However, rare doesn't always mean valuable when it comes to obscure characters in comic books. You never know though.