Hiya.
Even though it doesn't have the seam on the back that folks look for with older bags, it has appropriate marbles. I don't know what exactly the bag should look like in the early 1950's. But those are 1940's Alleys, which Berry Pink used to fill his bags in the early 1950's after he bought the Alley plant and turned it into the Marble King company. But before he developed Marble King's signature style.
I'll go look for an ad which might show them.