Dear Roger and JDS,
I've posted below the National Archives "WO" Harrison list, I think it all of them and between the three of us we have done about a dozen (I think) if you can remember which numbers you have done could you please cross them off the list in some way, I will do the same in the next few days
WO 374/31331
HARRISON, Lieut A
1914-1920
WO 374/31332
HARRISON, Capt A E
1915-1920
WO 374/31333
HARRISON, Lieut A F
1916-1920; 1923
WO 374/31334
HARRISON, Lieut A H
1915-1919; 1930
WO 374/31335
HARRISON, Capt A H
1916-1919
WO 374/31336
HARRISON, 2/Lieut A K
1915-1919
WO 374/31337
HARRISON, Lieut A L
1917-1920
WO 374/31338
HARRISON, Lieut A N
1914-1920
WO 374/31339
HARRISON, Lieut A R
1915-1919
WO 374/31340
HARRISON, 2/Lieut A R
1914-1920
WO 374/31341
HARRISON, 2/Lieut A S
1918-1919
WO 374/31342
HARRISON, Revd A S C
1914-1921
WO 374/31343
HARRISON, 2/Lieut A V
1915-
WO 339/51234
HARRISON A
[1914-1922]
WO 339/54918
HARRISON A
[1914-1922]
WO 339/83679
HARRISON A
[1914-1922]
WO 339/131387
HARRISON A
[1914-1922]
WO 339/132051
HARRISON A
[1914-1922]
WO 339/139173
HARRISON A
[1914-1922]
WO 339/6774
HARRISON J de C, Capt
1907-1916
WO 339/13223
HARRISON A, Capt
1914-1921
WO 339/25049
HARRISON A A, Capt
1914-1920
WO 339/41100
HARRISON A W, 2/Lieut
1915-1917
WO 339/61000
HARRISON A
[1914-1922]
WO 339/70076
HARRISON A
[1914-1922]
WO 339/70553
HARRISON A
[1914-1922]
WO 339/71139
HARRISON A
[1914-1922]
WO 339/77131
HARRISON A
[1914-1922]
WO 339/83679
HARRISON A
[1914-1922]
WO 339/98317
HARRISON A
[1914-1922
WO 339/109822
HARRISON A
[1914-1922]
WO 339/113906
HARRISON A
[1914-1922]
WO 339/128539
HARRISON A
[1914-1922]
WO 339/131387
HARRISON A
[1914-1922]
WO 339/132051
HARRISON A
[1914-1922]
WO 339/139173
HARRISON A
[1914-1922]