My father worked in Charlwood Park around 1950~1970. He was one half of the company Ashpool & Twiddy, a womens knitwear company, which was based there and as a young boy, I visited on a number of occasions. Here are some of my recollections:
1) It was quite a grand house and particulalry impressive inside with a large sweeping staircase that swept up inside the oval hall.
2) Douglas and Gladys Ashpool lived 'above the shop' using first floor rooms.
3) Ashpool & Twiddy used ground floor rooms for offices, stock and showrooms.
4) There were large cellars which seemed to be used for storing aircraft parts - mainly instruments obviously removed from planes and kept for some reason.
5) There was a large greenhouse between the house and the airport grounds which was in a state of disrepair.
6) The front door was mirrored by a dummy which makes me think it may have been a Lutyens building.
7) Ashpool & Twiddy was sold to Straven when my father moved the operation to Straven premises in Regent Street.

Doug Ashpool was a very keen cricket fan and knew many of the England players at the time and I believe he often met the Duke of Edinburgh who was also a keen follower of the game.
9) Doug suffered from a terminal respiratory illness from which he eventually died. In his later years he was bedridden in one of the bedrooms with an oxygen cylinder by his side. He was a very keen ham radio enthusiast and had a large motorised cuboid aerial on the roof which he could control from his bed.
10) Gladys went on to continue in the fashion industry and in ~1975 I met her (for the last time) in Paris at the George V hotel on the Champs Elysee where she had a small show in one of the ground floor rooms.
I would be very interested to see any pictures of the building, inside and out and grounds.