Just search.
They are available.
https://www.uhaul.com/Trailer-Hitches/1967-Plymouth-FuryI get about a dozen results with google, aside from Uhaul.
Verify that it will work with the wagon, before ordering.
I understand the situation, but it looks like it may be an easy solution for you.
The Nova in my avatar no longer has a hitch available. Those of us crazy enough to tow with them have to fabricate from scratch or adapt from a universal kit.