Terry, is that coupler a Madison Hardware creation, for their 700T tender to couple with postwar cars. If I remember, Madison made their 700T for customers who wanted a scale size tender for their 773 Hudson.
I have a 700E Hudson that I think is a 700EWX. It has full scale trim and blind center drivers. I do not have the correct tender, or at least not the correct coupler. A reay
went through Stout years ago (Don Hagar?), but I did not get a chance to examine it. Curious if there is just a modified manual hood coupler for the EWX tender or if the coupler pocket is also modified. I hope someone knows the answer to this.
I just found Don's video that includes the 700EWX and although he does not show the underside of the tender, he shows it coupling to a tinplate car, and it just looks like a manual rib-top hood coupler.