Melting gold requires SOME kind of "GOLDFINGER" type melting facilities. PIECE OF CAKE!! Right??
NO ONE would blink an eye because, SOMEHOW, you would be able to do all this without ANY help, witnesses, etc.
You would merely go into the local gold smelting joint, put down all these coins and say: "MELT THESE, PLEASE." Lol.
Wow!
A person could pick up a gas cylinder for welding at Home depot for about ten bucks and a brass nozzle for another $15 or so, then home melt the gold in any metal container that has a higher melt temperature than gold.
Not recommended in this case because of the rarity value of the coins, but it would be a piece of cake to melt gold without anyone knowing about it.