I am in the early stages of putting together my first 009 layout, based loosely on the Ashover light railway. Given that a major part of the rolling stock will be composed of D type bogie wagons , I have been acquiring some Dundas kits as well as a couple of Bachmann RTR models. I just wondered if anyone knew, approximately, when the change from the early wagon lettering scheme as portrayed by Bachmann to the later style took place?. Despite having a couple of old books covering the railway, can't seem to tie down when the change took place.
A quick search on Google reveals that there is a preservation society. Also, there's a Wiki page listing history and references for further reading...
Local libraries in the area(s) of a railway are often treasure troves of old photos etc as are the preservation society's members. A letter to the head librarians may bring in something useful.
Good luck with your project. Good research is never wasted !
Dave