You'll never know its origin. It could have been on the sleeve of Ernie Banks, Fergie Jenkins, Billy Williams, Ken Holtzman, Glenn Beckert, Don Kessinger, Bill Hands, Rich Nye, Adolpho Philips or Ted Savage. (I tried to rank them in descending order of stardom, though I'm sure someone will take issue, haha).
Or it could have been an "extra" that never even got sewn to a sleeve. Without provenance, it will always remain a mystery. Regardless, I love pieces like this. The Cubs sleeve patch is one of the true mid-century classics, along with the Screaming Brave, St. Louis Brownie, Chief Wahoo and Mr. Red.
Yours looks to be authentic, but do keep in mind that knockoffs exist. Here is one such modern example that is pretty well executed. It would not be difficult to age this patch by exposing it to the elements and running it through the washer a few times....
https://www.sportsworldchicago.com/c...emblem-source/