I have not seen this before, though I am familiar with the company, Oneida. Instead of the hallmark, "Oneida Sterling" , this simple plate, which resembles Queen Anne style, is marked, in plain caps, and in the centre of the back, ONEIDA SILVERSMITHS.
I am trying to date this, also, to find out whether this is also American silver. I thought it was Danish!
Do you have any clues, anyone?