This scenery uses the 1 metre terrain mesh that I discovered recently for the UK. Unfortunately this mesh is incomplete, which makes it difficult and fiddly to use because you have to avoid geoconverting the "holes" in the data. One good thing is that it is generally complete around the coast, so you could in theory work around the coast geoconverting level 12 sized areas. However in some places you'd still probably have to reduce the areas to level 13 or 14 in order to avoid the missing data.
About a week ago I applied to the Ordnance Survey to use their 5 metre data, which is 100% complete. I haven't heard back from them yet but, if I can get hold of it, this data should be almost as good as the 1 metre mesh - and much easier to use.
I've also been working on the building textures to bring them more into line with what you normally see in the western fringes of the British Isles. It's mostly about the overall colour and impression they give. At the moment I have 50% stone and 50% white rendered for this region - with greyish slate roofs.