Based on C&S 99201 at the Colorado Railroad Museum
The prototype at CRRM doesn't have couplers.. instead, it has a drawbar to the tender behind it, and the tender has a coupler on it's rear end.
David Wolf did an awesome job of animating this model.. check it out..
Kevin Smith also painted up one.. here's a video: https://youtu.be/jtv7ptc2fx4
The Rokuhan Shorty chassis will fit inside if you add some shims to keep it positioned correctly.