I have some folks planning an estate sale for my parents belongs and just wanted to be sure a antique furniture piece was given reasonable consideration to its uniqueness. It is an antique executive conference table acquired from Union Station railroad station in Chicago when they remodeled. My Dad worked at that location in the 70s.With no furniture manuafacture markings, the Corbin DF11 and DF4 locks on the drawers may be the only dating clue. I did look at the posted Cornin-Russkin pdf on keys and keyways...but could not make a linkage.Any thoughts on the date of the locks would be appreciated.Gordon