Firstly it's the 747-8 there is no need for the extra zeros
10 x 777 already ordered, first delivery April 2008.
Agreed the 787 is the logical choice for 767 replacement but getting advantageous line numbers will be the problem.
Last point -
DTVAirport wasn't suggesting removing the Chatham Flag design but the words "United Kingdom" from the side of most of the fleet.