Hello XH668
For Matching airfield you can try http://www.b26.com Their messageboard often has veterans from the 391st BG(M) posting there. As for Sawbridgeworth, precious few survive from the many squadrons who were posted there. We tried to contact as many as we could two years ago for the Memorial dedication day. I could sort you out some addresses to which you could write, the same same for Hunsdon veterans.

By the way, a forthcoming documentary programme is being filmed about Hunsdon and the Canadian night-fighter and Intruder squadrons based there. The final interviews with some of the aircrew involved, is being filmed on the 29th of March at Hunsdon.
The website you refer to is my own site, you can use anything you need for research material if it is for a personal thing.