I might mention that I doubt our lords and masters of this forum would object if you plugged your charitable auction, especially if there is some decent silver in it.
I once bought a 18th century tea water heater described as a Russian samovar at another charity auction
I note my initial comment on researching this mark was not universally welcomed.
In my defence I had already identified this particular mark at least once before on this forum (see below) and decided, correctly I think, that offering suggestions on inquiry search process might be more valuable to readers than duplicating effort already expanded.
CRWW