KZ440 timing advancer

Pertaining to the timing advancer mechanism off a '83 KZ440D5 . . . 

While cleaning and refurbishing this advancer (it was a solid block of rust) I mistakenly lost the "insert(s)" that fit into the notches on the weights (I hope my terminology is correct lol).

Is there a way to replace the lost inserts? What material are they? Phenolic? Metal?

Thanks in advance.

From a post by loudhvx the little pads are rubber and when missing the timing can be off. you'd need to check the timing with a timing/strobe light. His comment was in regards to a 550 but I would assume it would be the same thing w any KZ timing advancer.

I would try to use 2 - 3 ring layer of shrink tube to mimic the rubber damper pads.