here is a full page from a 1940's Pennant catalog. I contacted the ebay seller and they confirmed "Butler Bros" is printed at the bottom of the catalog
Here is the ebay description:
"This is a used 4 page brochure published by Pennant Brand. I do not know the age of this brochure but it is from the 1940's based on the autographed mitts from Bill Dickey, Dolph Camilli, Augie Galan, Billy Herman, Gabby Hartnett, Hank O'Dea, Eddie Marshall, etc. This brochurs contains photos, illustrations and prices of sporting goods. Some of the items are: baseball bats, softball gloves, baseballs, soft balls, uniforms, baseball shoes, tennis rackets, tennis balls, Stevens Bolt Action .22 Rifles, golf balls, catchers' mitts, basemen's mitts, fielders' gloves and more."
BretMan had a good point about the actual manufacturer of the Pennant brand. Rawlings was hinted at in the search but maybe someone has a better familiarity with these endorsed gloves and mitts and could add something.