It is not dated bit was published serially in the GWR Magazine in 1909/10 so would date to around then.
1942 Great Western Railway Shunt Wagon Label – “Shunt with Great Care”
GREAT WESTERN RAILWAY WINDOW LABEL GWR London Paddington-Great Malvern Trains
GREAT WESTERN RAILWAY WINDOW LABEL GWR Great Malvern-London Paddington Trains
