Answer back from the seller (and I need to upgrade my Ref. books) Club burned down in 1955 and wasn't re-built.

He has two of these dice for sale, with the dual 2's.

Now you have me thinking Terry, the double 5 and double 2 dice in combination might be the same as a pair of straight dice for rolling 7's? It's a little late for rational, or abstract math analysis, but it came to mind that the number of sides, although contained on two dice, would produce the same combinations.

However the possibility of shooting a hard 10 or hard 4 would be impossible.

Interesting probability question...