Duncan Phyfe Dining Room Suite

Duncan Phyfe or a similar type of Mahogany Harp Dining Room Suit. Drop leaf table with one leaf, triple harp pedastals with 4 side chairs with Harp back. China cabinet has glass upper doors, one drawer and two bottom wood doors. On the chair seats it is printed "78013-4407" and on the back of china cabinet it reads "Inspected by Plant 6 - 50,6,13" I am trying to find out more about the manufacture, the approximate age of the suit, (I believe was purchased in the 1940's), and the approximate value of the suit. This was my grandmothers and trying to decide if it is worth refinishing or if I should sell it. In excellent condition for its age, chairs need regluing, and table needs to be tightened up. Finish looks really good. Any information on this suit would be appreciated.