Rob,
That is the nicest looking "Fulton Coupler" I think I've ever seen.
I have an NOS Speedmaster Coupler but has some shelf wear and rust:
I went out and looked at my hitch...it is identical to yours with the exception I do not have any hardware so not sure of the knob/bolt orientation.
If you do decide to part with the little jewel, please let me know.
If it is ok I'd like to copy your pictures for reference and use it on my Bantam T3-C site link and will give you credit.
Was the Woody Trailer I posted above in Rantoul at the tractor show yours?