Yes, Charlton ended up obtaining 4 stories originally produced by an outside, New York studio for Timely, including a "Buzzy"(Bear) story, as they had always worked at least one issue ahead of what was ordered, and were stuck with extra inventory when Timely stopped ordering for those series, cutting down their Funny Animal lines in late 1946, and getting into the teen humour and romance lines. I'm not sure if Charlton bought them directly from Timely, or from the New York Studio who drew them for Charlton (Fago, Funnies, Inc., Baily's, or Comics House? - not sure which studio,). It's possible that Charlton's connection with Timely, Vince Fago managing Timely, and his brother Al's studio (of which Vince was still a partner) was what facilitated that deal.
Actually, Charlton had 3 different funny animal pig character series produced by New York Comic book art studios, specifically for them, during the mid-to-late 1940s. "Paddy Pig" (changed to "Pudgy Pig" after his 2nd appearance), started in Jack-In-The-Box Comics #1, in 1945, when Charlton was called "The Charles Company". He soon moved to Charlton's produced, packaged and distributed "Catholic Comics" in 1946, and ran there for several years into the 1950s. And they had "Piggly Pete" in their "Zoo Funnies" line in 1947 and 1948. "Pudgy Pig" returned with his own comic book for Charlton in 1958.
Ziggy Pig was a completely different character whose cheeks were much fatter. However, the artist who drew this Charlton "Tubby Pig" has a very similar style to one of the early to mid 1940s New York studio artists who drew several series for Timely, so that same artist may have drawn this Charlton story.
In addition to Ziggy Pig, Timely also had "Oscar Pig" (who looks, more than Ziggy, like this "Tubby Pig"), during the early 1940s. He appeared in "Terry-Toons Comics", produced and distributed by Timely's staff for Paul Terry Productions (as a Timely Comic under the Timely Comics imprint). Oscar Pig did not remain among Timely's characters after the Terry-Toons franchise moved to St. John Comics in 1948.
Link to the book: Jack-in-the-Box Comics 12