Glad you enjoyed the posting guys ; it's all true, too....
The respirator store was one of the more unglamorous buildings ; it was where gasmasks were unpacked and hung up regularly to prevent the rubber from perishing and splitting. The only major building left at Bourn now is the combined gymnasium/chapel. I've just found a nice aerial view from the flying club's website ; -
http://www.rfcbourn.flyer.co.uk/bourn.htm