My owners manual didn't have what I would consider a regular part # to pass along so I just called Weber for you. The whole damper assembly is about $2.50 for ea. damper you need. I didn't get an exact number because the computers were being updated so she couldn't look it up. They should be up and running soon for you to order they said.
I was either wrong on shipping or it has went up. Still not bad, $7 shipping for anything from a washer to a kettle lid. Kind of odd, but that's how they do it. I guess it is a good deal if your the guy that needs a lid.
So, just call them and tell them you need however many round damper assemblies for a 22 Â½ inch kettle. I will also add this, for some reason Weber is kinda odd about selling some parts to non-owners for projects sometimes. My advice would be to be ordering them to replace some bent ones on an old kettle.
It's just easier, but that's up to you. I myself can live with telling a little white lie to Weber.
Weber Replacement Parts--- 1-800-446-1071
Good luck and just let me know if you need anything else Phil.