well, i did get some from Numtich, but that was about a half decade ago ... when these wear out, I'll replace them with the bronze ones from Track of the Wolf.
for what it's worth, i've found that it's best not to get emotionally attached to nipples- they wear out and that's a cold fact of life, like the reeds in a bagpipe, it's an expendable part.
make good smoke!
oops! after posting, i looked on the Track site and it appears that they do have what you seek - give them a call 1-763-633-02500