What's nice about the this 1950 NL champs pennant is the amount of hand written script utilized on it. When I'm trying to ID a pennant, I look closely at the
artwork because I know, more often than not, the same artist produced the art featured across the series; and artwork includes scripts utilized. In the 1940s, the artist couldn't just dial-in whatever font they desired like you can on a word processor today; they had to make the font. It's extremely personal to the artist.
For example, if you look at all the pennants from Trench's stadium pennant series in the 1950s, you'll see the same unique script utilized for the ballpark name, e.g., "Sportsman's Park"; "Milwaukee County Stadium," etc. That script is essentially Trench's signature.
Your 1950 NL champs pennant features an entirely different script. It's definitely not by Trench's artist. It does appear similar to WGN's, as WGN's ca. 1950s ASG pennants featured a similar cursive script. Greg, compare WGN's 1950 ASG pennant featuring Comiskey Park and the AL/NL "book" roster. Similar cursive scripts, right? But compare the names "Roberts" and "Hammer" ... although similar, they appear different to me. Different "R" and different "H" as best I can tell from pictures....
Maybe you can confirm by giving us a side-by-side comparison, since I don't own either pennant?
Anyway, my suggestion: follow this unique script to a known pennant by maker, and you'll have solved the greatest pennant mystery of the 20th century.