Well, Westmoreland went to Citadel for one year, then to West Point. I queried Citadel because that seems to be conventional wisdom for its location...but the reply I got didn't confirm it (that's a nice way of saying...).

I suspect the knife may have been part of his estate and his heirs may have it. His papers are in the U. of South Carolina State library. Thanks for the tip. Regards. Oh.. If I find it and get a picture, I'll share it of course.