Gonzo, you of course are correct there and BA started flying trials of MLS @ LHR (27R)in the late 80’s. 757 IKK and 767 WND were both used at one point. I have had the pleasure of doing numerous MLS approaches in both aicraft and also in, if I recall, 1990 we did approaches for several hours overnight at LHR 27R in the FAA 727-100.