The BA trials at LHR were in the nineties, with one 757 (G-BIKO?) and one 767 (G-BNWB) with a chequerboard painted on the nose cone. The MLS was on 27R and could only be flown manually to CAT 1 minima, the main reason people requested it was when 27L was the landing runway and you wanted to use 27R to park on the old T1 shuttle stands...