I am no expert in any way, but have looked at a couple "Ka-Bars" over the years, never saw one marked M17
I guess the first thing to do is to make sure it isn't a fake. I saw at usmilitaryknives.com some years back where they have a page called The KaBar page that has pictures about "the most faked knife in the world" or some such.
A "real" Ka-Bar is for sure stamped Olean New York on one side. There were 3 other official manufacturers of the USN Mark 2 Fighting Knife, but only 1 has the claim of Ka-Bar, so the OPs could for sure be a real WWII Mark 2 USN knife, but the sheath would be gray and certainly not marked M17.
There were some post 1977 commemoratives issued with a 3/8" thick pommel that are the basis for a lot of the fakes around according to the fake page
Like other posts say....more photos and descriptions of all other marks on both the knife and the sheath may help and their is a bunch of guys on this forum that are really into these Ka-Bars so real expert help will be along soon.
