What is a Zenith Trans-Oceanic Model A600-A600L worth?

This radio is in pretty good condition, it has  some scrapes and is missing 1 peg foot and also the dial light is not working. Other than these issues it is rather good condition, my grandfather purchased this NEW in the 50's for $100(cant verify) and has been the only owner since, he asked to research it to see what it might be worth. It has the original owner/operators guide, original schematic for wiring and repair the original short wave broadcast time pamplet and an information pamplet that looks like it may have been attatched with some sort of twine or string prior to purchase.