I've seen these on a few Mk1 ones, I suspect its a suspension tweak by Toyota.

When you use roll centre adjusters they come with one pair 5mm thicker than the other pair so that the spacer can be discarded.

I expect that because of the age of Mk1's

(and because of the muppets who have worked on them in the past) many cars have had the spacers lost/discarded.
