Japanese Shibayama Ivory Paper Knife; Signed

It is painfully unfortunate that so much of the shibayama 'jewelry' is missing, especially as the signature chip remains...'tho I doubt it can be attributed.
This is 16 3/4" long, ~1 1/8" wide; the handle area is ~3/16" thick, the blade tapers from ~0.160" to ~0.100" near the tip along the central spine, with both edges quite thin, 'tho not sharp. The blade is translucent, as the last pic shows.
Now that I know these are not page-turners, I'll scour a few squirrel-holes for another couple of them...but they'll be quite plain; simple functional tools, without any embellishment save the craft in their fashion. Thanks for lookin'!

 

page cutter....letter opener......still nice !