For those interested in the June 1940 period in the United Kingdom, particularly Corps' Order of Battle, you might take a look at the CMHQ files at Heritage Canadiana. They are not complete but they give one a fair idea of non-divisional units during the period. There are lists for Artillery, Engineers, Signals, unassigned Infantry as well as Divisional Orders of Battle. The files start here (Reel T-17844 p. 1146): http://heritage.canadiana.ca/view/oocihm.lac_reel_t17844/1146?r=0&s=3 They end at p. 1417.