I am highly persuaded by that.
This seems like it could be an example of a box which someone would be tempted to refill the box to make it more "authentic" and in that manner lose a clue to something which we might finally learn more about many years from now.
I saw a Gropper ad which was said to have come from 1939 but it was for a Gropper top.
There also happen to be Akro marbles in the ad but no apparent connection between the companies.
Okay, now that is strange.
Akro Moonies are supposedly known for their glow.
Did they sometimes not have it? Was there an era in which they didn't? A narrow window of time when they didn't?