So this is kind of cool - I learned about a new type of artifact this week. One of the artifacts in the Cape Krusenstern collection is a tci-tho slate scraper. I hadn't heard of them before, but I did a little digging and apparently the name comes from hide-working tools used by Athapaskan peoples, who are spread over the northwestern part of North America.
Rounded working edges
I really need to emphasize that I don't really know anything about these tools other than what I've stumbled across online in the past hour or so and the reference photos that I was sent from Cape Krusenstern. My first impressions might be off, but I found a couple references to tci-tho and tci-tho-like bifaces in Matson and Magne's 2007 "Athapaskan Migrations: The Archaeology of Eagle Lake, British Columbia: Appendix I". The reason I found that reference interesting was that it mentions that a couple of the tci-tho-like bifaces tested positively for blood and fat residue, indicating that they were used for "flesh or hide processing".
A loose leather grip? Maybe?
The circular slate disc that I was asked to reproduce from Cape Krusenstern doesn't have any obvious signs of hafting, although this image of a stone scraper from the Bata Shoe Museum's online exhibit called; Tradition and Innovation: Northern Athapaskan Footwear shows a nearly identical slate disc, partially wrapped in cloth to create a grip. The scraper in the Bata image has a little more polish on the edge than the disc I'm working on, but otherwise its pretty much identical.