Sarge,
Up until August of 2004(somebody correct me if I am wrong). The Nevada gaming commission wasn't enforcing a rule about numbering strikes. In that month the head of the Nevada gaming commission changed. And it was then decided to start enforcing this no numbering rule. After this date you will find NO numbers on any silverstrikes.
A good examble of this. Is the Bill's Tahoe $200. There is some that was minted before this change and numbered up to 100. And there was a few minted after this change with NO numbers on them.
As for the value of numbered 1's or not numbered 1's. This depends like anything else. How many there are and the collectors interest in them. And what is a collector willing to pay for 1. The NO numbered Treasure Island Sirens is a good example of this.
The Bill's Tahoe no numbered might be more valueable. Because there wasn't very many no numbered 1's. But, not necessaryly just because they wasn't numbered. I hope you understand what i am trying to say.
I believe the TI Sirens would have been a high $$$$$ $200 dollar strike. Wheather it was numbered or not. Because, of the small number of them. Along with collector interest. And the way they was handed out.
Dan