vintage bakelite mouthpiece for candlestick or oak wall telephone

Old candlestick telephone vintage, bakelite and steel mouthpiece. This measures about 3 1/4" across and about 2" deep. It is marked inside with "5-45", "635A" and "M". The contacts inside look to be silver plated. It is missing one of the small screws that hold the steel housing to the bakelite body. We have not tested this and are selling it for restoration or parts.