Found North Denes in 2001 Pooleys. Runway 28/10 - 480m grass but do not allow fixed wing traffic (they did some years ago).
Instrument approach is probably an NDB one - no indication of anything else.
I am ceratinly not a local but drive past quite a bit and have often thought how convenient it would be to land there. Norwich is next best option for that part of the world I think.