Best possible way I found out is to scope around locally or the areas in high you which to hunt. If it's private it won't be a problem as you can simply as the land owners directly face to face and get permission. Be ideal to swap phone numbers and details. Always worked for me and my dad year ago.
Sorry. It might be the fact I can't read proper England.... but are you saying to just go out on private land, and when caught, ask the land owner if it's alright to shoot over the Land?
Sorry again. May it be my none language understand of English.