To me it looks a lot like a Gutmann Cutlery knife. Edge Brand, G.C. Co., Explorer brands. Never seen the ENCO stamp but I suspect it is a Gutmann. Anything stamped on the opposite side of the blade like Original Bowie Knife or Original Buffalo Skinner smooth?
Doug
The words vintage and antique are vague. Actually most words are vague. Even the word vague is vague. Pocket Knife Art