I think I have to custom make a hitch for mine but still doing some research.
I had one made locally for my 59. They put a "tank bar" on it for added capacity which went right under where a spare tire would have originally gone. It worked great though and towed a lot of stuff over the years. (biggest load shown in the link, and not recommended though) http://i1152.photobucket.com/albums/p494/69B-Cuda/1958%20Viking%2060/DSC_8607.jpg