Anne,
You are just repeating what I was pointing out "Whopper" = "Large, it was around during my childhood too which I think pre-dates yours.

I find it hard to see why Burger King an American Company would name one of their products after a very small district in a city three or four thousand miles away. Wapping becomes Whopper? It does not make sense.

Also I doubt that Burger King had access to your 1767 references. But am willing to be corrected.