Yes - but for how long? The Cockney accent has changed substantially since the days of Dickens, when one of its features was the exchange of V and W (e.g. werry instead of very). There are cockney songs of this style in broadsides of the era - see All around my hat, which starts:

"All around my hat I Vear a green Villow"
and then mentions "Wegitables"


Incidentally, I don't know how old Rhyming Slang actually is, but I have scoured the Bodleian collection without, so far, finding a single example in any song. Does anyone have an earliest recorded date?