This shot was taken in the Paramount studios gymnasium, circa 1937 (which was a barn on one of the back lots.) Steve McQueen was famously photographed training in the very same gym a few decades later.
Also of note is that fact that barbell plates and equipment from just about every other equipment company, including those who were older, are fairly “common” in comparison to this set. I know of no one who has even seen a single Narragansett Barbell or plate in the flesh, let alone owned one. If you should come across any, please let us know.