Bruce Robertson RAF serial book (Midland 1987) has them Wellington Mk.IC Z8771 and Z8772, latter be DW.1 (DWI ?) version. Two flew out in August 41 (by OADU) via Reykjavik and Gander, I have both arrival times in Reykjavik, but not tie-up or departure of first one (Arrived from Prestwick 30.07.41) but other "Experimental Long Range Wellington" flew west 21/22.08.41. Mk.IV is discussed below but MK.IC engine cowlings show in video. One Wellington shows twice in video if you look closely.
Ed
http://www.rafcommands.com/forum/sho...t-Wright-Field