Doubt they'd have scale plans, but vehicles in 1/72nd scale, kit and diecast, should be available. As for various buildings, there are a few kits from different manufacturers, including Airfix. However, White Waltham was, and is, a civilian airfield, the 'home' of the ATA (and Fairey, as you know) during WW2. This means that the buildings, hangars etc, were of civilian design, and different in style to the RAF type which, from the Expansion Period of the mid 1930s, were built to set patterns, these again differing if 'permanent' or 'for the duration'.
I can certainly provide info/drawings on the standard military patterns but, from what I've seen of WW, they wouldn't be of much help.
EDIT: Forgot to add; some model railway buildings kits can be adapted, such as warehouse and garage kits etc,