Vintage Montage Game

Hello,
Does anyone know about this game? I purchased it at an estate sale. I can't find it anywhere on the internet. The game is called "Montage" and the front of the box has "Made in U.S.A. There is no company information or anything else. The first photo is the box. 2nd photo has the pegged numbered cardboard pieces, and 3rd photo has the peg numbered cardboard pieces.

The board:
Measures: 12" tall x 11-1/2" wide. On the left are the numbers 1 through 12. That's how many pegged pieces there are. There are metal arrows that can point to "U" or "E". I'm thinking those might stand for "Uneven" "Even"?

It looks like you can slip something inside the cardboard in the middle. Then you put the cardboard pieces in there. I noticed that these numbers have the same shape: 1&6 2&7 3&8 4&9 5&10 11&12
Perhaps that's were the "Uneven" and "Even" numbers on left correspond?

I'm dating this circa 1930's - 1940's.

Any information would be appreciated. I am so curious about this!!!!