I inherited an old duncan phyfe table and the only markings on it are the Jefferson Woodworking company stamp. The table hardware with drop leaf works perfectly. Its pretty cool that your family's table slides are still working and are identifiable. Do you know if they made slides for the duncan phyfe tables? The JWC stamp has words: Jefferson (then a logo - badge shape) then words: Table Slide. Would this give the approx age? I am trying to decide whether to have the table refinished, any information would be appreciated.