Seems like it would be pretty easy to make if you take the ATI kit or some such and weld it on a frame with pins.
I've thought of doing the reverse with a QA female plate and parts from a harbor freight QA - island tractor has something similar from Millonzi. It puts 3ph on the FEL.
I'm happy enough to just run Skidsteer stuff on the FEL. Yeah, it requires a big tracotr, but only a big tractor has the hydraulics to make SS stuff work. Otherwise you are better off getting a skidsteer type implement that's been modified to run off the PTO.
JJ, I am consistently impressed with the pictures you put up! Your pic library (or search skills) are impressive! (as is your knowledge)