This hotel surprisingly still exists (2011). It's quite a bit bigger than it looks. It had a fancier name for a bit, "Le Meridien Excelsior Heathrow Hotel", but now it's simply "Park Inn Heathrow".
Taken by my grandfather David C. Cook on the way to a visit to Moscow for a meeting of the International Electrotechnical Commission. Scanned from an unlabeled Kodachrome slide numbered 6 in a slide cartridge marked "Russia".