If you look closely at the above pic you can barely see the tail of the "C" in CASE as it comes around and under the "A". 
Under that you can kind of make out ESTED (which I naturally assume is part of the word – TESTED)……

By viewing tang stampings on CASE knives in pocket knife reference books this is the style of stamp used in CASE knives produced between 1920 and 1940 making this knife at leat 71 years old!! That's how, in my scientific evaluations and calculations I made this determination!!

Quite a piece of American made steel spirit fulfilling our lives some 70+ years later!

I have this knife up for auction on eBay right now, ending on 7/30/11:

Saturday Steel Sahlute!