That’s Museum of Design in Plastics, and their online collections are really outstanding. While there is some good online info on hornworking in the hobby community (especially the SCA), it’s mostly text with simple line art. I couldn’t find much photography of real artifacts or tools before discovering MoDiP’s online Nature’s plastic exhibit. Their collection shows off both the kind of work that’s traditionally been made in horn and the tools and processes used to make it, and is on loan from The Worshipful Company of Horners, a London trade guild that traces its history to the 13th century.
Working with Horn: Resources at UK’s MoDiP