Further to what WHBM says, the aircraft with the pull down bunks were the Constellations as the Argonauts were never so fitted. The Stratocruisers never appeared outside the Atlantic routes apart from a brief operation to West Africa in 1958 and 59. This was to counter growing criticism that BOAC was abusing its monopoly position on the colonial cabotage routes and giving the newly emerged Nigeria Airways ( then WAAC) and Ghana Airways outdated equipment when they started long haul services to London. The Stratocruisers then gave way to Britannias. Sadly the Stratocruisers never ventured further east, although en route to Nigeria and Ghana they did give the citizens of Rome an interesting alternative service to London in competition with BEAs offerings.
Between London and Singapore, the Constellations and Argonauts soldiered on until the arrival of the Britannia 102s in March 1957 although these only had a life of just over 2 years on the route until the arrival of the Comet 4s from June 1959. The 50s were an incredibly fast moving decade with BOAC fleets such as the Hermes 4, Comet 1 and DC 7C lasting only 2 to 4 years at best and in contrast the Argonaut spanning from being in the passenger fleet at the same time as the York right through to within a month or two of the 707.