I decided this afternoon to hand-polish a silver-plated serving tray that belonged to my grandmother, and I became curious about when and by whom it was made. None of the marks listed on this website seem to correspond to the one on the back of the tray. I'd appreciate hearing from anyone who can identify it or who can estimate when the tray was made or how.
I don't know anything about silver, I'm afraid, but the tray appears to me to be merely silver-plated. The copper-colored metal underneath the silver shows through in the raised portions of the design, either by intention or through long use, and also in a few patches where the silver has corroded.
I'm attaching a photo of the entire tray, a close-up of a portion of its design, and a close-up of the mark on the underside. The mark features a coat of arms surmounted by a crown or jewel of some kind, two laurels beneath, and the numerals "4 22/2" beneath the laurels. Inside the coat of arms is another coat of arms, showing a flame, and three objects that might be daggers or fleurs de lys.