Almost answered my own question, but further information welcome:
The Stores Depot, Milton
Maj. D. DAVIES asked the Under-Secretary of State to the Air Ministry if he will state for what purpose the Didcot depot is being used, and how many persons are employed there ?
Maj.-Gen. Seely: No. 3 Stores Depot, Milton, near Didcot, is used for the storage of aeroplane spare parts, raw material, soft goods, and canvas hangars. The strength at the present time is 1,648, and it is intended to reduce this number by December 1 next to 1,221. This is one of the three stores depots which it will be necessary to retain for the R.A.F.” Flight 6.11.1919