Editing GWR 4073 Class (section)

===New builds===
The new-builds were as follows.{{sfnb |le Fleming|1953 |p=H17–H18}}

Great Western Railway
*Lot 224: Nos. 4073–4082, delivered August 1923 to April 1924.
*Lot 232: Nos. 4083–4092, delivered May to August 1925.
*Lot 234: Nos. 4093–4099 and 5000 to 5012, delivered May 1926 to July 1927.
*Lot 280: Nos. 5013–5022, delivered June to August 1932.
*Lot 295: Nos. 5023–5032, delivered June to August 1932.
*Lot 296: Nos. 5033–5042, delivered May to July 1933.
*Lot 303: Nos. 5043–5067, delivered March 1936 to July 1937. (Nos. 5043–5063 were originally named after Castles, but were renamed in 1937 after Earls)
*Lot 310: Nos. 5068–5082 delivered June 1938 to June 1939. (Nos. 5069 and 5070 were named after [[Isambard Kingdom Brunel]] and [[Daniel Gooch|Sir Daniel Gooch]]; In 1941 5071–5082 were renamed after aircraft used by the [[Royal Air Force]])
*Lot 324: Nos. 5093–5097, delivered June to July 1939.
*Lot 357: Nos. 5098–5099, 7000–7007 delivered May to July 1946.

[[Western Region of British Railways|British Railways (Western Region)]]
*Lot 367: Nos. 7008–7027, delivered May 1948 to August 1949.
*Lot 375: Nos. 7028–7037, delivered May 1950 to August 1950.
These locomotives were built with minimal changes to the dimensions. However, from 5013 ''Abergavenny Castle'' there was an alteration to the shape of the front-end casing over the inside cylinders, and from 5043 ''Earl of Mount Edgcumbe'' a shorter chimney was fitted.<ref name=KCGWR/> Those built before 1926 were fitted with a {{convert|3500|impgal|abbr=on}} tender but thereafter {{convert|4000|impgal|abbr=on}} became standard for the class.