Hi Bruce - I think we may have a few extra pieces of the series.
I know we have the set of 9 strikes in that series .....

They were issued by the Sheraton Hotel/Casino in Robinsonville, Mississippi
The casino opened it's doors on August 1, 1974 & closed on December 17, 2009

The complete 9 piece strikes in the series consists of:
#1 - Apollo
#2 - Challenger
#3 - Galileo
#4 - Gemini Capsule
#5 - Hubble Telescope
#6 - Mercury Capsule
#7 - Soyuz Rocket
#8 - Viking Lander 1
#9 - Voyager 1
These were minted by Sunshine Mint (S)

If you like space related - we have 3 sets of the Las Vegas Hilton
"Space Quest" .... See pictures below and link to my Ebay store ...
If you are interested in anything in my store, contact me via my
email - not thru Ebay so I can pass along some savings ...

Al Varelas / USMC
SS-1654
alvarelas@gmail.com

MY EBAY STORE:
https://www.ebay.com/str/usmc1965

"LINK TO SPACE QUEST SETS - Around 6.5 ozt (over 1/2 lb)of .999 pure silver / "Mother Ship" (center) is 4 ozt - 1/4 lb .999 pure silver"
https://www.ebay.com/itm/HARD-TO-FIND-5-Pc-L-E-Hilton-Casino-Space-Quest-Set-Las-Vegas/264095419323?hash=item3d7d504bbb:g:gakAAOSwzFhcGrW2