Replacing Jimny Kingpin Bearings

Preload shims go on the outside of the bearing between the inner race and the shoulder on the swivel pin.
I suspect the water gets into the bearing from the inside.

I would look more at getting the water out, with a crafty drainhole somewhere.

Preload shims go where they are intended to go (or not go, in the case of the SJ series).

As pointed out, the current available preload shims for the Jimny are intended to go between the inner race and the kingpin shoulder.
My proposed top-hat shim(s) would go between the bearing's outer race and the shoulder of its location in the axle.
The end result would be the same, size for size.
It was just an idea of trying to combine a means of preloading the bearings whilst, at the same time, preventing water access to the kingpin bearings.

Just a thought.