I have been watching this thread with great interest as I find the Pacific Northwest especially fascinating, and the more I look at this unusual dagger, which indeed appears Tlingit, I feel more that it may possibly be a more votive item. While I cannot claim any special knowledge on artifacts from these regions, I wonder if this may have any association with the well established 'potlatch' ceremonies common to these tribes. The potlatch was a ceremony which eventually replaced actual warfare, in which prominant tribal figures sought to gain distinction and favor in various situations by competing to see who could give up the most wealth in lavish giveaway ceremonies (discussed in "Keepers of the Totem", Time-Life, 1993, p.151).
The dagger itself, while in Tlingit form, seems 'decorative' rather than for actual use in the way the totem figure is attached to the tang of the knife, especially as it is simply a facade and open in back. The blade, being of copper, however crudely made, may have been significant because of the copper alone.
The apparant high regard for copper, and its use particularly in potlatch ceremony, is discussed in "Crossroads of Continents" Ed. Wm.Fitzhugh & A.Crowell, Smithsonian, 1988), in the following article paragraph:
"...objects of particular wealth, which were often decorated with crest designs, were the shield shaped sheets of copper. 'Coppers' were appropriate as marraige or potlatch gifts or as the purchase price for land. All Northwest coppers that have been tested are made of European copper, intended for or used as sheathing for ships bottoms. Although some copper may have been scavenged by the Indians from wrecked ships, most copper was obtained from European traders".
from "Tlingit: People of the Wolf and Raven"
Frederick de Laguna, Fitzhugh,op.cit. p.62
While the typical form for these objects is described as 'shields', perhaps more innovative and traditional objects such as this dagger representing a clans warrior heritage may be considered as possible potlatch offerings?
I think that many of these items of not necessarily great age from distinct ethnographic groups maintain considerable integrity and interest for the symbolic purpose for which they were intended. This example certainly seems to have such potential, as always, more research !!!
Best regards,
JIm