Sometimes though I can't be bothered to fire up the steam train so I bought a HGLW diesel shunter kit. This works fine except for the self shredding gears. Sharp burrs left on the brass worm wheel were shredding plastic off the worm gear, the underside was coated in white specs, perhap this is why they give you two worm gears. I had to dress each tooth at each end with a needle file and polish it with a Dremel.
The loco proved too light to haul the Mamod coaches around the bend on Mamod tracks (liberally lubricated by the steam loco). So I cast a couple of lead weights to go underneath.
The bonnet and exhaust are my additions.
Paint job is a little rough, more filler needed on the joints, but it's cheap enough for the kids to wreck without me shedding any tears.