Mid century modern table and chairs - need help identifying please

We purchased the table, leaf, table pads, six chairs and hutch from a neighbor when we lived in a small community in NW Florida and used for for a couple of years before buying a new table and chairs. We have decided to sell the table and chairs (and maybe the hutch) so I wanted to get an idea of it's value. It's been a challenge trying to locate any information about the stamp on the underside of the table or about the design. Hopefully someone here can assist. The owner of a furniture restoration company in the local area told me that this would fall into the "mid century modern" style and that the set is walnut, but not much more than that. The stamp on the underside of the table reads:

396-69-400
LARGE LEG TABLE
CONTOUR ARAGON WAL.
JOB 71

I have included a picture of one of the chairs and the table top and underside. Legs are square and tapered. The chairs have been reupholstered by my wife and do not have the original fabric. Any assistance on this would be greatly appreciated.