Perhaps the earliest "crows beak" butt made? Not sure, but most definitely on a fighter. While WWII vintage, note the peened tang on a brass washer, only time I have seen that IIRC. Belonged to actor John Carroll, the original Zoro amongst many others including Flying Tigers with John Wayne.
Mitchell has mentioned Cornish, but I don't know. I think all the Cornish sheaths I have seen were marked as such, but that doesn't mean it isn't a Cornish. Is sure looks like it could be, but perhaps that was the style for other makers as well. Hard to say.
New member and 1st post. My Dad's #1 which he got during Naval Aircorp training in Pensacola, FL in 1944. Not the original sheath, but it's been with the knife for as long as I remember. He tried to polish it with a dremel before giving it to me ~ 10 yrs ago (image2) and scuffed it up pretty bad, not realizing that it may detract from value. I have gently restored it by hand polishing most of the scratches out. I would like to get an accurate sheath someday. Thanks for looking!