Well, it certainly seems that they let the campaign die, now didn't they. I apologize for the extreeme time that has gone between the original post and my reply ... I think that it's not Thread Necromancy, considering the nature of the request, so, I hope that it's deemed acceptable.
I have loved all the Nyambe material since I originally got it, but since I am more of a collecctor than anything, I haven't had the opportunity to use it until now. I am using it much in the same way that Nothern Crown does, but I am using it as source material for the continent of Hepmonaland in the D&D World of Greyhawk setting. At any rate, I discovered that the Player's Lorebook predated the main Nyambe core book, so there's not a lot tha tI can imagine is in the one, that's not also in the other, but, nevertheless ... I have a copy of it, but it is also now ditributed freely on the Atlas games site ... [edit: Link removed because the Atlas homepage for Nyambe has a dead link].
Hope that helps!! ... and maybe generates a little more Nyambe traffic on the forums!
EDIT: It appears the link provided is broken. However, looking at my pdf copy (I'm sure this was never in print as it is obviously a preview type document), I agree that it is highly probable all the information in the Player's Lorebook ended up in the Core Rulebook
Thanks for the reply! I really appreciate the effort. I scrounged around the 'net at the time I posted above and I believe I found the lorebook using the Internet Archive site! I'm going to check the pdf at the link you provided against what I have. At least folks can perhaps find it easier now that this thread has been answered.
I've never played Nyambe myself, but I have the core rulebook and the two (?) supplements printed for it. I was very impressed with it and would love to use it in a manner like you. It's also strong as a stand alone campaign (it's original intent, of course). Coincidentally, I've been playing in a Greyhawk campaign for the last three years.