Supermarine Spitfire (Griffon-powered variants)
Production

Mark
Built by
Numbers Built
Notes
F Mk XII
Supermarine
100
First Mk XII 13 October 1942
F Mk XIV, FR Mk XIV
Supermarine
957
First Mk XIV RB142 28 October 1943
F Mk XVIII
Supermarine
300
First Mk XVIII June 1945
PR Mk XIX
Supermarine
224
First Mk XIX RM626 May 1944
F Mk 21
Castle Bromwich
120
First Mk 21 LA187 27 January 1944
F Mk 22
Supermarine, Castle Bromwich
(27) + (260); 287
First Mk 22 March 1945
F Mk 24
Supermarine
54
First Mk 24 March 1946

Question: When was the first Mk 21 LA187 produced?
Answer: The first Mk 21 LA187 was produced in 1944.