Here's a clue: (fill in the gaps)
"In later years ........ was used primarily for cruising, although she did not receive the major conversions to cruising of sisters Carmania and Franconia. From 22 February 1967 until 10 May, ....................... was chartered to the Cunard Line. She was carried on the deck of the ........ and supplemented the cruise by running trips from the ship to Athens, Beirut, Istanbul, Tripoli and Lisbon. The experiment was not repeated."