I think making the "Vintage Model" was pretty astute marketing by Rigby.
As you recall, when the "Big Game" model was introduced, it left a lot of potential buyers disappointed that Rigby didn't really stick to the pre-war design which was touted as their design goal with the Big Game rifle from the start.
Now, with the Vintage, they have heeded all of the criticism and instead of incorporating those changes into making the Big Game what it should have been from the beginning, they came up with a whole new model in between the BG and the London Best, at a substantial premium over the base model.
Makes sense, I guess. I wouldn't want to be one who bought a BG and then Rigby goes and improves the line on subsequent rifles. Nobody would ever buy your gun if that happened.