Hello Tom,
Yes, there were (12) different characters made into Silver Strikes.
The early (1993 -1994)set had only (10) but the later (1997) Sets had (12) Characters.
You can see these strike photos and mint info from the Home Page and the Strike Online Catalog under Hilton after Nevada, not Las Vegas Hilton.
Let me know if you need any help in finding the missing strikes from your collection.
Regards,
Gene