There is one Case/Bose knife per year, and some in that run have different handle material. (Bone, Stag, Pearl & Abalone)

There are two production knives, the Sowbelly and Saddlehorn. Some of these knives are made in limited runs called SFOs (Special Factory Orders) I think. There are so many to keep track of and it would be next to impossible to collect them all. Knife clubs from all over the place can contract these as well as big dealers that want something special.

Hope this answers your question