All info I can find about the ship not sure if any help and I don;t know really where to suggest looking as it apears no lists were kept after 1960
P & O Line
Between 1890 until 1960, a complete record of ships arriving and departing the UK were kept by the Board of Trade. These lists have recently been digitized and present the most straightforward and uncomplicated way of searching for passengers.
After 1960 The Board of Trade was no longer required to collect passenger lists after 1960, although lists may have been kept in some overseas countries or ports beyond this date. For their own purposes shipping companies would have continued to compile passenger lists, but in most cases, these records have not been retained.
After 1960 it was no longer a requirement for shipping companies to deposit passenger lists with UK authorities, and neither P&O nor the UK authorities have any passenger lists after that date.
http://www.poheritage.com/ RANGITOTO / ORIENTAL CARNAVAL 194921,809 gross tons, length 609.2ft x beam 81ft, one funnel, two masts, twin screw, speed 17 knots, accommodation for 416 single class passengers.
Built by Vickers-Armstrong, Newcastle for the New Zealand Shipping Co, she was launched on 12th Jun.1949 and started her maiden voyage London - Wellington on 25th August.
1965 the mainmast was removed and a small tripod mast fitted to the funnel to carry the after steaming light.
1966 1st Jan she was painted in Federal Line colours and was officially transferred to Federal Line in 1967.
1969 August sold to C. Y. Tung's Orient Overseas Line, Hong Kong, operated by Oriental South America Line and renamed ORIENTAL CARNAVAL.
1970 Used on a Round the World service out of San Diego.
1975 Laid up at Hong Kong.
1976 Feb scrapped at Hong Kong.[Merchant Fleets, vol.7 by Duncan Haws]