Very difficult to see what is happening here. Alphabetical Roll has him as LC. The only entry for an "L C Pearce" in WO338 is for "Louis Courtney Pearce" without a regiment. There is only one Louis Courtney Pearce on British Births and Censuses, who applied for a commission, but did not get it.
The Leave Book has him as "J G Pearce" But I cannot find an RAF Officer with those initials.
There is however a Leslie William Charles Pearce who was an RFC Officer and appears to be the man we want. A Lt in RAF.
1899 Jul 22 Born Edmunton, Middlesex
1901 census at 299, Wightman Road, Hornsey
1911 census at 28 Princes Avenue Wood Green N
1916 His RAF record shows him to be a "private clerk" to his father before enlisting
1917 Nov 8. Commissioned 2nd Lt.
1918 Jul 31 Missing taken. Interned :Holland
1918 Nov 12 . Repatriated
1920 Nov 29. Joined ADRIC with service no 1136, Posted to L Coy
1921 Feb 4. Discharged Cork Hospital
1921 May 16 . Dismissed the force "theft"
1921 changes his name by deed poll to "Pearce-Gervis" His mother's name was Foreman, I cannot see the connection with Gervis
1921 Apr/Jun Married in London to Marjorie M Vander Vord as Leslie William Charles Pearce-Gervis. 2 daughters born - Anita in 1924, and Jacqueline in 1940. The electoral registers do not show him living with this wife at any time.
1930-1939 he is a poultry breeder Leslie Pearce-Gervis
1939 Leslie William Charles Pearce-Gervis, serves in WW2 and comes out a Group Captain. He served in West Africa at Air HQ in Freetown . Wg. Cdr. L. W. C. Pearce-Gervis Senior Personnel Staff Officer H Dec.43
1947 Jan 16. Commission resigned. Wing Commander L.W.C.PEARCE-GERVIS (76324 ) retaining the rank of Group Captain
1947 Jan 29 Departs to India from UK . Leslie William Charles Pearce-Gervis
1966 Nov 9. Died. Probate to David Pearce, Civil Servant
WO 339/120767 for L C Pearce.