GK430
Quite possibly, because I 'spotted' G-APNB and that was almost certainly at Heathrow. Both aircraft were Britannia 317s, both registered 9.5.58. 'NA was withdrawn from use at Baginton on 31.5.72 and scrapped in July '73. 'NB was w.f.u. at Luton in March '71 and broken up the following November.
In the 1960 edition of Civil Aircraft Markings, both aircraft are shown as belonging to British and Commonwealth Shipping Co. (Aviation) Ltd. Would that mean a Heathrow base? By the 1971 edition, both aircraft are owned by Donaldson International Airways, presumably at Luton.
Hope that helps. Please see your PMs for a little more.