...Little Rissington a stones throw from London, nearby road and rail access...
Rissy?
1. It sits on a hill.
2. It has short RWs which cannot be lengthened.
3. Rail access is very limited - just Kingham station on the Cotswold line via. a narrow lane.
4. Road access is poor - A40 is a nightmare west of Oxford and A361 / A429 are cross-country single carriageway roads.
5. Neither M5 nor M40 are readily accessible.
6. They'd never get planning permission.
Are you sure you weren't thinking about Upper Heyford? Close to 2 main railway lines and only 4 miles from M40 Junction 10.