That's the way to go to the pivot on the truck , because everything else swings wide on the turns. I have a similar problem to resolve on the pull car. The coupler is attached to the frame and swings too wide on the turns and derails the flat car.Dave Smith on the CTT forum did one a few years ago. He used a piece of steel and bent it so it would go under the cow catcher and fasten to the pony truck. Then he attached a coupler to the steel piece on front of the cow catcher. No modification was necessary to the loco except for screw holes to attach the steel piece to the pony truck. I thought it was pretty slick, but then a new problem arose: How to keep the cars coupled together as the post war knuckle couplers won't stay coupled if there is too much load on them. I managed to keep about 23 cars coupled together a few years ago. You can also put the 2nd loco in the middle of the train and sometimes that works.
The T man has, but in a different way.Has anyone modified a Lionel 224 to add a coupler to the front to double head?