All of this hallmark guessing and make-believe is cracking me up. As one who sells work abroad and knows a tad about the long lines at British precious metals assayers office, I can Hallmark whatever the heck I want. The Hallmark is my symbol, telling the world either who made the piece or who assayed it. However, when I stamp it with a metals ID (or "strike"), then it gets tricky. Only in Britain do you "have" to have a stamp on precious metal, but the assayers has to do it. And, you only have to do it if you want to say what the metal is. Which for some jewelers this becomes important.
However, if there is another metal soldered or attached to the precious metal "that I want to mark," I have to id that other metal also, thus I can buy stamps for copper, brass, bronze, nickle, etc...
The Brits are about the most anal retentive about marks, hallmarks and such. But anyone can have a hallmark by itself. That is just your signature. I can hammer that hallmark on metals, briar, plastics, paper, forehead, anything I want.
But, for the metal to be assayed as a form of silver in Britain it also has to have a silver strike telling the jeweler that will work on it what type of silver it is, .925, SS, CS, .800, .750, argentium, or a unicorn.
In the US, it is just easier to Not mark the metal, but if you do, you just add your hallmark to it as your signature.
In other words, hallmarks aren't what you think they are. It's the metal mark or "strike" that becomes a legal document.
I know, this is a long response, but in my laughing at the responses, I was trying to figure you guys out. Where do you guys get these ideas?