Morning everyone. Looks like there may have been a misunderstanding regarding RTR or kit building. From my needs in a model engine, a flywheel drive is a must, why? To give a momentum effect when running,also smooth out the running on less than clean track.Having seen how some US outline HO diesel and steam outline models run with a flywheel each end of the motor, this high standard is what I am looking for. Have only found it in one British out line steam outline model, that is the Hornby J15 0~6~0 locomotive.Most RTR diesels have this,Why not the steam locos? Now with the cost of RTR escalating, a kit built loco is soon going to become more cost effective,especially large GN mainline steam, Pacifics etc.