Quote Originally Posted by Jedi-Loreen View Post
I think that's foam, probably with a sticky back. That's what it looks like to me.
Yeah, that's exactly what it was. It's like an open cell neoprene that came in a sheet. I just cut it in thin strips with an x-acto knife and a ruler, and laid it in the grooves. Wasn't that hard at all. The only problem I had is that it shrunk away from itself a little where the ends met. You can see it in the photo.

I may end up replacing it with o-rings, but I'd have to cut one and glue the ends where the screw hole is.