If it is the Vietnam era 1917 it will be made by either General Cutlery (marked Gen Cut) or Canadian Arsenals. I am not sure how these would be marked, never had one. Have had the Gen Cut models. They are marked on the guard NOT on the blade. If this is Vietnam era I believe it may not be a rearsenal. All the Gen. Cut. bayos I have seen are of the dark parkerized look. The grips should be checkered plastic. These bayonets are also a little crude by the Winchester and Remington standards of WWI. The scabbard should be fiberglass with a metal throat that is marked U.S.-M1917 and the makers initials-B.M. & V.Z.M. seem to be the most popular, could also be marked B.A. or V.R.
If the scabbard is a WWII fiberglass it will be marked M1917 and have the ordnance (flaming bomb) on the throat. I usually see the Vietnam bayonets in the $175-$225 range, and they all seem to be in minty condition.
Hope this helps,
Tuco