These marks are on an ashtray that has a Hong Kong Silver Trade Dollar (or a coin that purports to be such) set into the centre. Does the mark in fact indicate 900 silver and is the coin genuine? Thank you.
Hi, 90% is close to sterling (.925 or 92.5%) silver fineness. 1930 was minted in London (no mint mark) and Bombay (B), over 6 million and 10 million respectively. Anyway, there is no numismatic value in the coin. Regards