here are some shots of the Hallmark Freedom Train PA loco ornament i fit over an MTL GP chassis. i smoothed the sideframes of the MTL GP trucks (got them pretty thin!) and glued the PA sideframes to the outside. I fit N scale Concor metal wheels to the ends. the nose and tanks sides i glued directly to the metal shell, and used styrene sheet in the roof and sides to insulate the mechanism. no mod was required to the MTL chassis -- i can still pop it out and put it right into a GP35 or GP9 (replacing the stock side frames). haven't weighed it yet. can't find my scale. dave f.