I have many postcards. Some with relatives. This was before my time. I have seen a great ashtray from Diamond Jims in Jackpot Nevada but nothing with his name for downtown. There are just Nevada Club trays & they are not too rare or expensive. Nevada Club & Diamond Jim's Nevada Club are the same place, the name was just added in the mid 60's. Sounds like you are on your way to a big collection. There are probably 2,000 or so trays. Who has the most? I have about 1,000, mostly older for all of Nevada. I have heard of collections nearing 2,000.