Good observation. Well ... I never thought of that banner (or the similar Dodgers and Yankees versions) as being a strong candidate for Trench; but, I certainly couldn't rule them out. They do look alike, don't they?
Unfortunately, these banners were all made pre-1957, which is about when Tom Storm's father purchased Trench. When I last spoke with Mr. Storm, he could not recall ever making banners (or, "rectangular pennants); but he wasn't really involved in the company until the early 1960s, well after these were made.
Whoever did make these banners, I believe they only made them for the league champions in '52 , '53, and '54, correct? Are there others? I can't recall ever seeing a '54 N.Y. Giants banner that complements this Indians one. But if one was made ... I know two guys who'll know
Here's the only vintage photograph I know of showing a banner like this:
https://pennantfever.weebly.com/who-we-are.html
This photo was taken in the center field bleachers at Yankee Stadium during the '53 World Series. I believe there's ample evidence that Yankee Stadium, in the mid-1950s, was a Sport Service ballpark. If so, that makes it more likely this banner was supplied to them by Trench.