Hi Ralph,
Here is information on what you have. this is from the
2018 Nevada Silver Strike Reference Guide ...
As of June 18, 2018 it has a value of $80 - $100

Here is detailed information for a collector:

Casino: Caesars Palace
City: Las Vegas, NV
Denomination: $25
Design side: Marquee
Logo side: Caesar's Palace, $25 Eating Grapes
Edge: Full Reeded
Series: Gaming Tokens of the World
.925 Sterling Silver
Mint Mark: F
Mint: Franklin Mint
Issued: 1978
Notes: 1.5 Oz. Proof

Al Varelas / USMC
Vietnam Veteran
Silver Strike Collectors Club SS-1654