Help with unit identification

The picture is Bovingdon.

ted wrote:

The picture is Bovingdon.

Totally agree there; I know Bovingdon very well as it was my 'local' airfield where us local ATC cadets (I was in 2204 Chesham Squadron) could scrounge flights, plus in the mid/late '60s, 613 VGS from Halton did several detachments there usually (but not always) when Halton itself was too muddy to use.
The first detachment commenced on 21 Jun 1965 when Sedbergh XN 150 and Mk3 WT 871 were aerotowed Halton - Bovingdon courtesy of the Chipmunk glider tug belonging to RAF Halton and the last was on 5 Mar 1967 due to the pending re-cladding of all 4 of Bovingdon's hangars and the imminent arrival of 617 VGS who had been required to vacate Hendon.
I was pilot i/c for the last flight by 613 at Bovingdon in Sedbergh WB 970; I had been in the front seat of WT 871 for the first launch from Bovingdon and in between I had gained my Air Cadet Soaring Certificate (BGA 'C' Certificate) at Bovingdon in Sedbergh XN 150 on 19 Sep 1965 as well as flying numerous cadets on Air Experience flights.