Hi, Thanks. The Innerleithen Co-op wagons were also NBR registered but ordered in Brown Bauxite so I will probably hold fire on this project if there is more definitive data out there, albeit currently out of reach. One other interesting thing about the Innerleithen wagons is the when empty plates which were return to Leven Colliery Fife. I am not sure what was special about the coal from the Kingdom which got them to haul it through most of the Midlothian coal field. The pits at Rosewell would have been visible from the train.
Regards
Paul