This is just a daft request, highly modified Minis with LSDs were said to be heavier to drive than any of the US muscle cars in the British Saloon Championships in the '70s due to the very short driveshafts they were mounted on.
A locked diff in any car intended to go round corners, let alone a Mini 1000, would be too heavy to drive in reality, if you were strong enough to turn the wheel it would just rip the diff to pieces on tarmac.