To the best of my (admittedly leaky) memory I have never seen an actual paper issue of this series. I have the copies that kind souls have scanned and that I have downloaded from the Digital Comics Museum (thanks, guys!) They came out in the late 1940s and early '50s, the first 35 by Kelly, the rest of the series by Del Connel and artist Al Hubbard (whose work looked a lot like Kelly’s and is an artist I think is underrated).
Today we have the first one, published in 1948 for the Bakers Associates, Inc. by Dell, and it is all Kelly, front to back. If Kelly ever wrote about this project I haven’t read it, and I wonder if he was given carte blanche to create characters and storylines. It has the distinctive art Kelly is known for, but not the humor. This postwar comic is about an ongoing war between the good guys and the bad guys, and bad guys who sometimes act like good guys. It was aimed at children, after all. It takes place in miniature, in a forest setting, perfect for Kelly's facile imagination and drawing style.