Culpeppers sells elk antler and mosaic pins, but no moose antler. The mosaics are under rods, pins and rivets.
http://www.knifehandles.com/
Jantz sells lots of different sized mosaic pins, but no antler. They sell just about every other kind of exotic handle material like giraffe bone or zebra bone plus all kinds of african horns.
Oh you are talking about a specialized mosaic pin with a moose or bear depiction in the pin. I never knew you could buy them, I like the scorpion one. I did not see a bear or deer.