Fuller's Index confirms that The Western, New Western and Apache all used 124 Fremont as their addresses. The SS Rex used 128 Fremont, but I can't tell from our postcards if there was anything between the Rex and Boulder Clubs.

As for roulette chips, we have a postcard of a roulette game at the Apache. Luckily it's a real photo post card so, using a jeweler's loupe, I can make out a generic design on the chips. That doesn't necessarily mean anything, as I believe that sometimes they used 'prop' chips for the postcard, but it's also possible that's the chips they used for roulette. Another older Las Vegas mystery, that helps keep the hobby fun!