Motivated by the conversation, and with an element of avoiding decorating, I've put knife to plasticard to produce Root and Shaftoe Mining Co. loco number 1:
Lots of detail work to add, but I'm waiting on the decoder to arrive to finish the mechanical/electricals before getting too involved. Not that there will be much detailing, this is very much stand-off scale suitable for outdoor use. Lighting will be directional.
The pantograph arrangement is very much temporary for the time being to check clearances against a proposed loading gauge. The top deck is detachable, to allow access to the spud mounting screw and the decoder bay. It will also allow swapping between overhead pantograph, trolley pole and battery-style compartments (so in a sense, this is R&S locos nos. 1-3).