A nice find at the local Oxfam bookshop - a 2 volume set (foolscap I suppose) of the official HMSO description of the British Army orbat for the whole of WW2!
As well as more "conventional" organisations, the books also have things like who were the garrison units in all of the out of the way places across the globe who probably never got around to firing a shot!
There are also two annexes at the end, one with a detailed orbat for El Alamein, and a second for a detailed orbat of Overlord!