Sawzilla, Sawagain, lots of places to order parts.

Just gotta know where to look.

I've used a lot of proline parts, as good or better than OEM Stihl, and the best part, they're available.

https://sawzillaparts.com/proline-av-buffer-mount-set-for-stihl-028-028av-028-wood-boss-chainsaw/

I prefer peace. But if trouble must come, let it come in my time, so that my children may live in peace. ~~ Thomas Paine