Jeffrey,
I gave you the reference to Bakersfield, because TGT had that listing for "Johnny", like your dice.
The casino in Wells, that is being discussed, is spelled "Johnny's" in some places and "Johnnie's" in other places.

Your dice could, of course, be from the Wells club (the Aladdin had at least one order of dice with their name mis-spelled, could have happened here too)....

or from a club that no one's mentioned (such as Johnny Dollar's Saloon & Dance Hall [location unknown])...

or could be "name" dice (we have dice from Harold's Club that don't say Harold's Club, they say "Ray I. Smith")...

Maybe NH is the reference to the club, and "Johnny" was the owner (TGT lists "NH (Gentlemen's Club) 807 S. Mirage, Lindsay, CA USA, Mold: HHR, Opened: 1971 Closed: 1973)...

TGT also lists "NH (Nancy Hall)" ordered personal chips in 1964, maybe she got dice too, and Johnny was her husband....

There's lots of possibilities, good luck finding the right one!