@jumpa check with some shops. I used to save the spherical washers (which I assume is what you're looking for). If you can't find anything, let me know, and I'll dig through the crap I've got lying around...
I have a bunch of Avid stuff CPS, bolts, adapter, ... you can have what you want. I'm away until Sat in NH for work though but you can ping me and come by to grab whatever you need.