Barnstormer
Lucky you. I would love to see one in the flesh (it's the spotter in me).
They still operate from Mildenhall from time to time. There was one there for a few weeks last year, keep an eye on the spotter's sites.
Remember pulling out a
very heavy lump of something from one of those holes in the floor at the Wittering ASU once; it had a T-handle embedded in it. GRSF Chap wanted to calibrate a geiger counter with it, but had a wrist in plaster so went along to help.