on the website Medicine Man Gallery, this hallmark (or one super super close) is attributed to Herman Hoskie. here is the link, look under Herman Hoskie. But in Bille Hougart, 4th ed he is listed but is attributed with just etching or stamping his name. If you look for works by him on the internet you don’t find mosaic type inlay work. There is another Hoskie (Ervin) that does inlay like this but his mark is completely different and Hougart does not say that they two men are related.