The San Juan Car Company AAR Type-E coupler is available in two different shank styles. The traditional style (#5101) fits Kadee coupler pockets. The other style (#5104) has a scale shank. At first blush, it doesn't seem to be very easy to adapt to equipment. Jim Hickey came up with a nifty idea for using this coupler. He built a coupler pocket that suspends the shank with a 0.030" wire pin and uses a coil spring to provide centering. Jim Zwernemann sketched the design based upon the original Hickey implementation.
The whole pocket can be made out of styrene strips for the side walls. You can use trucks springs or even Kadee coupler springs to provide centering and some amount of cushioning.