Hi Tom,
Although we are not supposed to note items in auction in progress, I cannot resist noting the possible significance of this unusual item. This is what is known as a 'makiri' ,an Ainu mans utility knife, and of extreme importance to the Ainu man as it was used to craft his everyday and religious items.(see "Ainu: Spirit of a Northern People", Fitxhugh & Dubreuil, 1999, p.292,fig.42.8). Given its provenance, it may be associated with the St.Louis Exposition of 1904, where a small group of Ainu produced items which were sold, and is where the item shown in the previously mentioned book was acquired (also of crescent shape).
Good to see you posting
All the best,
Jim