Many vehicles, including Land Rovers, had driver side vs passenger side springs. So it's not always a joke.

No Joke......really..
on my 1952 series one land-rover, the leaf springs were different from side to side, the drivers side had more camber than the passenger side.
I definitely know this because mine always had a lean.
I removed all the springs and compared on the bench, the difference being evident immediately.
I then installed the correct springs to the drivers side and the lean had gone.
Land rover made the drivers side camber tighter to compensate for driver and petrol tank weight, because you sat on top of the tank ...
An update re my rear springs, Wadhams have replaced them with a pair of equal size, all I have to do now is wait for it to stop raining so I can fit them!!