Tonight I primed and painted the loco frames and in addition cropped the motor shaft so the 1424 will sit comfortably inside the Smokebox.
Having performed these tasks, I placed the body on the chassis to check the fit which appears to be bob-on.
Some hint of the weight and mass of these beefy Locos is transmitting itself into this model; I think this is evident from the sit.
The model weighs a (metaphorical) ton and between that and the motor/gear combo I suspect it will pull anything I care to fling at it. Testing day at Wharfeside may be entertaining!