There wasn't much left of Leiston 28 years ago which was the last time I was there. My parents had a static caravan on the airfield from '77 to '88 and every year more of it disappeared. I believe the runways were only ever concrete and by then there were just a few odd narrow bits left for tractors etc.
I started this intending to suggest Martlesham Heath and Woodbridge but I only ever saw them from the ground. BT owned some or all of Martlesham by then and I don't know how much was left of the original airfield.