You're correct about Stephen C
Yes, the Vulcan was in three hangar, and as you said Steve was testing for leeks from the door seal. And yes his financee was working in sick quarters, and she did not recognise his body. I recall the incident well as I was working in the Hydraulic and Tyre Bay when the accident happened - on night shift on 17 September 1969. I thought one of the hydraulic jacks I had serviced recently had blown, when I heard the noise. Steve was an SAC and only 20 years old at the time. He was a good mate of all the riggers in the hangar. A very sociable young man. He is buried in Haycombe Cemetery in Bath, Somerset.