This one is a 30 strike.

I've never run across a full book of either of them.

Notice the phone number. It appears they had a "party line"! During conversion to full dial, some phones had a dial like this so they could pass on to the switchboard operator the Party Line suffix to complete the call. Some towns were still on manual as late as the 1950's but I don't know the cutover date for Las Vegas. My parents in small-town Missouri still had a party line in the late 1950's... 612W .