Firstly, the Mercury has never won a world championship (the 85 worlds was won by Gil Losi Jnr driving a modified Yokomo YZ834b Dogfighter).
Secondly, the original Mercury was manufactured by Mugen, and wasn't released until late 1987.
The Academy version is simply a re-badged knock-off, not the original.
There was one on ebay a couple of days ago.
I wouldn't call it legendary either, they were bloody awful cars
(I know, i had one