Has anyone tried to build a "working" Spooner's boat? 3d printed boat and chassis with wood strips to build up the profile... still very much a work in progress.
pictures on Flickr (https://flic.kr/s/aHBqjCkGyP)
Some years back I did give some thought to making one, or somthing like it, using a Kato Protram chassis.
I have a 3d printed wagon chassis, and have kitbash built a body... For "power" I'm using a long "draw-bar" being pulled by the end of a train with a traditional loco.
I think I have seen one - poddibly not in 4mm however.