W. Adams & Co. Dinnerware

Q My grandmother got a W. Adams & Co. dinner service as a wedding gift in 1916. I only have the tureens and serving plates and wonder if they are worth anything. The serving plates have some ”age” spots but the tureens are in perfect condition. The dishes are marked with a crown over a circle with a pretzel shape mark in the middle, the words ”crown, semi-porcelain,” and ”W. Adams & Co., England.” We’d like to know what they are worth and how to sell them.