I think that this particular Simplex kit was only ever produced in a O16,5 format, but could be fitted with either a Tenshodo Spud (high-speed!) bogie or a home-made (scale-speed) chassis. It was possible to construct the home-made chassis to 14mm gauge (which I did).
When Roy gave up manufacture and distribution of these early kits (which included a Bagnall 7” 0-4-0ST and some hoppers), he passed them to Wrightlines. Kay Butler certainly sold a few of the Simplex kits but I don’t think that they ever formed part of her normal range.
David Woodcock
Champlon, Belgique
