R.K. Maroon wrote: ...snip... Note that the couplers pivot on the king pins, but are not fixed to the trucks. This is one of the tells of a Mi-Loco model. Did any other manufacturer do it this way?
Weaver's three-rail couplers were done that way, so easy to two-rail; remove the couplers, install KD couplers, change the axles, done.
EDIT: Weaver designed the three-rail "system" after the original two-rail system was in production. The tooling did not have to be modified.