Dating silver plate marks
One concave line represented 140/1000 fineness, a straight one 150 and a convex one 160.
For example, a Diana head within a frame made in the shape of a 5-petal flower represented 5x160 = 800 thousands fineness, a local silver standard commonly used in table forks and spoons.
Search for the words “Reed & Barton.” Another hallmark often used by Reed & Barton is a series of three marks. This is flanked by an eagle mark on the left and a lion passant (walking lion) mark on the right. If your piece was made from 1928 to 1957, it will have one of these date codes.
French silver made for export carries an assay mark in the shape of the head of Mercury, along with a number to indicate the millesimal fineness: "1" for .920, "2" for .840 and "3" for .750.
French silver also is punched with the mark of the maker.
Like most silver products, Reed & Barton silverplate pieces feature hallmarks that help you to identify it.
From 1928 to 1957, pictorial marks representing the year were added to the hallmark, which can further help to date a piece.