I am going to chime in on this discussion. I use silver plate trays
quite often. I saw them up, and put patina on them with a torch.
Sometimes there is brass, copper, pot metal, and who knows what under
the thin layer of silver. Sometimes the silver just burns off,
sometimes it mottles up into a beautiful patina. But every time you
put the torch onto it, it will change. I solder with silver wire when
I need to solder it. Silver will fill in the gaps, it doesn’t care if
the metal is “dirty”
But if you want to use a fork, and have it look like a fork, and
stay shiny, you will have to go with cold connections. If you google
my name you will see some of the things I have done, I don’t have a
web site. I am in Indiana.