Plans & Drawings
GWR Loco drawings - part of the Great Western Archive
GWR Coach drawings - part of the Great Western Archive
GWR Wagon drawings - part of the Great Western Archive
Barrowmore - This site includes BR official drawings of locos & rolling stock and much more for the late 1970s
N Wales Wanderer - Various drawings of British locos etc
LNER Encyclopaedia
GWR 4 and 6 Wheel Coaches
Various GWR drawings - locos & rolling stock
GWR Signal Box Diagrams (track plans)
Paints & Liveries
Station Colours - provides sample colours for various railway company buildings
Paul Bartlett's photos of railway rolling stock
Wikipedia UK Railway Colours
Other Aspects of Railway Modelling, Real Railways & Connected Subjects
Goods & Not So Goods - An overview of railway freight operations for modellers - A great site covering all aspects of railway goods modelling.
Great Western Archive - This site contains lots of useful details and photos relating to the GWR.
British & European Cars Guide 1950 - the tabs along the top of the page take you to some very useful background histories and information on earlier models.
Railway Signs & Signals of Great Britain
The Signal Box - Railway signalling
Complete Database of BR Locos 1948 to 1997