GWR 47XX CLASS LOCOMOTIVE KIT
BRIEF HISTORICAL DETAILS
George Jackson Churchward's final engine design prior to retirement in 1921 was this mixed-traffic 2-8-O with 5' 8" wheels. They were to prove to be outstanding performers and most imposing to watch at speed. 
For a detailed history of this long lived class, Part Nine of The Locomotives of the Great Western Railway published by the RCTS is essential reading.  
Other sources of information include:
Railway World, January 1966, contains a very interesting article by R.C.Riley.
An Article in the first edition of Great Western Railway Journal (Wild Swan).
Great Western Eight Coupled Locomotives by David Maidment (Pen and Sword)
An article in the HMRS Journal Vol 18, No.9 by Bob Miller

VARIATIONS POSSIBLE WITH THE KIT 
Cab roof.  About 1927 the cab roofs were extended at the back. 

Snifting valves.  The position varied as indicated above. 

Cab spectacle windows.  These were plated over during the late 1920's.
 
ATC equipment.  This was fitted to the entire class between 1/1930 and 7/1931.
 
Smokebox chin step.  There are two different designs. 

Lamp bracket.  This was moved to the smokebox door in 1934-37. 

Vacuum pipe.  Originally this was tall but later a shorter pattern was introduced. 

Pony truck spring housing.  Originally uncovered but subsequently fitted with a bell shaped cover. 

TENDERS 
When built the engines were paired with new (probably!) 3500 gallon tenders of standard Churchward design with visible, snap head rivets, on the tanks and coal plates. At least two (4704 & 4706) were subsequently fitted with Dean 4000 gallon tenders with flush rivets until all the class were paired with new Collett 4000 gallon tenders, which became standard for the class.