The National Archives has 15 WW2 items for R.A.F. Sibson in AIR records, mostly relating to accidents.  Units mentioned are:
2 Central Flying Training School, 1941
7 Advanced Flying Unit, 1942
16 & 17 Service Flying Training Schools, 1942-1943
4183 Anti-Aircraft Flight, RAF Regiment, at Sibson & Watton, Operations Record Books 1942-43
2859 Anti-Aircraft Sqn, RAF Regiment, returned to England July 1944 and based at Sibson