duncan phyfe drop leaf sofa table

Great grandmother's table from very early 1900's said to be Duncan Phyfe mahogany drop leaf table. Very good condition, still works great. It measures appx 28 1/2" tall 17 1/2 deep when shut and 46" when the leaf's are up and length is 36". I'm wondering how much this would be worth. There is a 3928 stamp underneath and a sticker that says Brandt furniture Hagerstown, Maryland.