I've used Deenethorpe in the past. Called the number in Pooleys (Estate Office) and got permission.
Just a long, straight runway with a road the one end.
Try their annoying website.
http://www.deenepark.com/index.htm There is an email address at the bottom plus fax numbers. NB NOTE this is a link to the estate who own the airfield. They were the people who granted me PPR
h-r