Hello Samantha,
Holly Hill House, Meopham, Kent was a private house in 1965 and indeed it still is, I lived there with my parents in the 1970's.
In 1965 a Colonel Trousdale lived there with his wife; she had been a Miss. Whatman of the Whatman art paper family; their paper was used by Constable and other notable artists. They had bought the house from a man named Cripps-Day who was a cousin of Sir Stafford Cripps the politician.
When Col. Trousdale died the house was sold to a Mrs. Audrey Trollope and subsequently to my parents.
I hope that this helps you a little. There are other dwellings in the area which are also associated with the name Holly Hill; Holly Hill Cottages (some of the old staff accommodation for the house), Holly Hill Lodge (the old gate-house for the house), etc.
Regards, Nicholas