Overland's models are nothing special, that couldn't easily be duplicated or surpassed, in plastic.
Maybe, raise the bar, knock out a model with working trucks(suspension-wise) you don't need real brakes; and, put small electric traction motors on each axle.
Build a locomotive model that actually performs similar to the prototypes.
If it's a 6 axle model, make it a working 6 axle model.
Rick