
You have two PNCs (Postal Numismatic Cover, or the correct term Philatelic Numismatic Cover) produced by a 3rd party - Modern Coin Marketing. They were probably sold via television, newspaper or magazine ads. I don't think that there is a great premium associated with the PNC, but I'm often wrong.
The dollar coin is not especially rare but is 0.500 silver. Slabbed examples can be obtained for about $20.
https://en.numista.com/catalogue/pieces10973.html
The medal is more interesting. Also 0.500 silver, it's much more uncommon than the dollar. Mintage is not listed on Numista: https://en.numista.com/catalogue/ex...a241868.html Check ebay sold listings to get an idea of its value.
Inordinately fascinated by bits of metal with strange markings and figures