Consider other sources of aerial imagery. For Norfolk there is historical and recent available via the County domains. The recent is unlikely to be more up to date than gargoyle. Also consider using the gargoyle streetview as that is often more up to date than the aerial in rural areas. Other sources of imagery are greenfruit aerial view (and whatever they call their street level stuff), Here, Bing, Ordnance (note the spelling) Survey probably use Here or Bing but you'd have to check. Scotland has it's own very nice aerial imagery online.
Other counties often have maps and aerial views, including hsitoric stuff, available online. Most Counties/Unitary Authoritys have their Definitive map online. Whilst the online version is not the legally binding one it will be kept up to date and as such is very good for rights of way.
Then there are council planning departments, estate agents etc. Often these will use individual aerial imagery sourced separately from the well known ones...eg. estate agents using quadcopter footage.
Really are spolied for choice now if you bother to do some research.