I did a little bit more to it. It looks so old-fashioned that I think it would be good as a rail car chassis. I'll hopefully get it finished this weekend. I changed the original motor to another K's Mk2, which still had both ends of the armature shaft intact, as I thought I might have a go at doing 4wd. Then I realised the motor was too close to the front axle to accommodate the gear. I haven't done any soldering at all on this yet, I've been using JB Weld.
