These spring washers are called Thackery Washers, and on a vintage Flying Squirrel there is one on the pivot for the hand gear-change lever, and one each side of the rear stand. Hard to find these days. They are still made but in far too thick metal for the Scott fitments.
I got the rear stand thackery washers from Richard Blackburn. My friend need this for Indian, but I will order some for the gear change lever as well. Hope it will be suitable and work well. Thanks for the infos