Wayne, I respectfully disagree . Somewhere on the forum, a while ago there was a discussion about the English and German knives with that material, No one really knew the process and I can't find any technical explanation of how it's done.
My own study of the material leads me to say it's bone. Here are some reasons why.
-The scale material has tiny remains of capillaries. Bone has a rich supply of blood to nourish it because bone is alive and can grow and repair itself. It also acts as a calcium reservoir to store and release calcium for other metabolic functions.
-Horn is not living tissue and therefore needs no blood supply. Chemically it is keratin, a protein found in hair, nails, skin etc. It is secreted from living epithelial cells, but once formed is "dead" like the outer layers of human skin. (Cosmetic companies and their customers don't like to admit this.)
-I have looked at both horn and bone microscopically and they are not at all similar . The horn structure is like a linear bundle of keratin fibers with no blood supply. A magnified look at our fingernails illustrates this. Bone is a calcium salt of hydroxylapitite, secreted by bone cells in concentric layers and richly interspersed with blood vessels and microscopic canals. The cells remain functional until the animal dies.
-Horn, and yes bone, can be softened to a great degree with heat and chemicals and easily formed and bent.
I'm not trying to play the expert here. My background is Biology and Physiology so the discussion appeals to me as a collector and a science guy. I don't offer this as "proof", just evidence.
Some pics and illustrations: a "pressed"- scaled knife and carved horn item and my own rough sketches of each microscopically . My best opinion without a chemical test is the scales are bone.
Hope someone can add to this discussion. I'd really like to know how it was done. They almost appear as if they're made individually for each scale.

John O'.