I don't have as of yet a feller buncher but I do have grinder that uses teeth comprible to a feller buncher tooth, I've designed and made my own teeth, I saw several problems with the current teeth and most are designed towards to company making them cashing in on sales of repeat business. I've known several operators who have rebuilt a couple of teeth designs and basically it wasn't cost effective from what I saw, they didn't have the setup to do large scale rebuilds and it coulnd't compete with large scale manufacturing of new. I like teeth that are through hardened not case hardened and am not real impressed with the square tooth design of some of the cutterheads out there. Don't know if that helps you or not but if your doing the research I'd have to tell you theres a big market for an better idea than whats currently being used in my opinion. I could help with the idea of the rebuild and how to go about it but I still don't know if its cost effective or not to be done and afterwards how that would affect the hardening process and the durability of the tooth in general.