From Anecdotes of the English language [etc.] by Samuel Pegge (1844):

. . . But, after all, the most striking and most offensive error in pronunciation among the Londoners, I confess, lies in the transpositional use of the letters W and V, ever to be heard where there is any possibility of inverting them. Thus they always say, weal instead of veal; and winegar instead of vinegar; while, on the other hand, you hear vicked for wicked-—vig for wig; and a few others.
. . . The following little dialogue is said to have passed between a citizen and his servant:
Citizen.—Villiam, I vants my vig.
Servant.—Vitch vig, Sir?
Citizen.—Vy, the vite vig in the vooden vig-box, vitch I vor last vensday at the westry.

Or, as the famous movie star waterfowl Greta Grebeo said, "I vant to be a loon!

That particular aspect of pronunciation in London seems to have died out in the 19th century. Dickens has some of his characters using it, but I've not come across it in any 20th century writing.