The first DC-3 variants operated on BOAC routes (Lisbon,by KLM crews) were the KLM escapees in 1940 which had Wright engines and starboard pax doors , arrived in neutrality orange , then camouflaged with British civil registrations (there was one DC-2 with them). BOAC started getting lend-lease Dakotas (C-47 double portside doors) in 1943. Camouflaged initially, they started stripping them around 1945
Dutch D C 3's, Schiphol, early 1940. by Etienne du Plessis, on Flickr
https://www.flickr.com/photos/8270787@N07/16476630568/in/album-72157605269786717/
https://www.flickr.com/photos/biblarte/albums/72157624029292187
http://www.famgus.se/Postcards/Aviation/Airports/FAPC-Airports-Sweden.html ....colour postcards 59, 607,608 show a NMF BOAC Dakota at Torslanda Gothenburg around 1945
A few of the aircraft used by BOAC in Africa \and on the Horseshoe route seemed to have escaped camouflaging
The first BOAC emblem appeared on Empire boats Clifton and the rebuilt Corsair in 1940 and also on a NMF Lodestar in the Near East
links and theorizing and graphics here:
http://theflyingboatforum.forumlaunch.net/viewtopic.php?f=15&t=565
BRITISH OVERSEAS AIRWAYS CORPORATION AND QANTAS, 1940-1945.. © IWM (CNA 3627)IWM Non Commercial Licence