That's NOT a Colt Single Action Army. It's a non-firing replica of a Colt SAA, made out of pot metal, a TOY!
The rest are all curios and relics, most are black powder muzzle loaders which would be legal in the US for anyone to own.
Ditto to that - I have one that came from a relative's estate that may become part of a wall-hanging in the mancave.
Actually, antique muzzle-loaders and antique obsolete calibre metallic cartridge firearms are still legal to own in the UK without a license too. I have a friend who owns several just as wall hangers. You can have them legally as long as you don't try to shoot them. For that you have to get a Firearms Certificate.
The people who handed these in were probably frightened housewives. It's a shame because they could have sold them to antique firearms collectors. What a waste for them to hand them over to the Police to be paraded in front of the public and then melted down. No self-respecting gangbanger is going to carry one of those pieces of garbage!