Found the article in the July 2006 issue (No memory problems yet it seems!) . The No. 35 Squadron flew to the USA from July 8th till August 29th 1946, with 16 Lancasters still painted in the 'Tiger force' colours. (And one York for technical support.)
The official name was 'Operation Lancaster' but is was also known as 'Operation Goodwill'. They flew from Britain to the Azores on towards Gander and then started a tour that led them from New York to Buffalo, Detroit, Chicago, St Louis, Kansas City, Denver, Long Beach, San Antonio, Washington and back to New York.