Bernard Rice's Sons Martini Shaker, Dist by S&G Gump, numbered Apollo E.P.N.S 5144, Stamped with date on bottom and on lid. I believe it is silver plated. In very good condition, with minor loss of plating on handle. Very similar to picture posted (I found the picture on the internet, will try to load an actual photo ASAP.
It was a gift given to my mother in the 1970s for her wedding by my father's Great Aunt. I am not sure how long she owned it before she gave it to my mom.