To me: first use John: Ticket to ride, George: Yes it is: with volume pedal (if it's not the Rickenbacker 12-String!),
solo in "If You've got troubles", introduced by Ringo "Oh, rock on anybody" (was there any trouble when Paul played the solo in Ticket to ride?
) and many, many more. There are photos in the Babiuk book (Beatles Gear), John with his Strat (p.159), and a black and white one (p.164). Here, the sonic blue looks pretty white and the headstock looks quite dark, similar to the photos above.
So to me, so far, it is John's Stratocaster on the photos above.
Wolfgang