It looks as if the Cobham site evolved from Fairmile Marine during the war according to this:
Noel Macklin - Wikipedia, the free encyclopedia
with the oil testing laboratory moving there in 1968 from this:
Emerald | Industrial Lubrication and Tribology | AOL 74: Admiralty Oil Laboratory Comes of Age
I never visited the Cobham site, but did drive past it on a few occasions.
Looking back, I was very fortunate with the variety of departments in which I worked. The move to Pyestock was just the result of lucky timing, whilst the move to UAVs was the result of constant badgering of all and sundry by me. The move to night vision was down to a fellow model flier in the establishment club tipping me off about an as yet un-advertised position being created in a department which did lots of trials work.
Even so, compared to Mechta Senior's variety of work, starting as a Flight Test Observer in Sunderlands to see how hard they could land (alight?) one (until they broke it!), flying in the Comet after they started crashing and before they knew why, a trip to Sudan in an Ashton to test air conditioning, and a spell on HMS Eagle doing noise testing, mine looked a bit tame.
It was a great place to work, and for many of us it was as the song says, "you don't know what you've got till it's gone".