Antique signed sterling Union Jack tie or lapel pin

About 2-2/3 inches long, this pin has an enamelled Union Jack on its oval top.The pin itself is ridged to help hold it in place. Marked Sterling and M.Co. - I believe the head of the pin is masking an F, which would make mark that of the Finberg Manufacturing Co., known for its jewelry dating back to the turn of the last century. This little pin is in good shape, with patina. Cross listed in Women's and Men's markets.