These maps are fabulous. I'm sure like other map makers, there are deliberate 'mistakes' on the maps to aid with any potential copyright issues. Ive found one 'mistake' on my BMC Harvey's Lake District map, but I'm not saying where it is! I too like the shading, it looks fairly similar to a 1927 O.S. 1" mile touring map I have of the Lakes which I want to get framed and hung on the wall. Its good that Silva Type 4 compasses now have a 1:40,000 romer scale to compliment these maps.
These maps are truely fabulous but you try buying one in Hereford it,s damm near impossable . the only place that does sell them is Waterstones and then you have to order them and at least two weeks .
Buy them direct from http://www.harveymaps.co.uk/index.html