I'm a bit late in replying but I flew Luton-Belfast Harbour on Capital's Short 360 G-OLGW on 21 March 1989. I also did Luton-Amsterdam on Netherlines Jetstream 31 PH-KJB on 3rd April 1990. I hope that helps with the dates. I seem to remember the Shed came back at around FL100 which led to some ear-popping on descent.