According to the Author it was a short lived mark,,,, 1961-63 would be my guess,,, someone might come along with better info. As far as
value,,, it's condition and with no sheath hurts the value. Myself I just liked fixed blades with the correct sheath. I have one like yours, Woodcraft,
Stag, mint with a mint sheath....Not for sell now, but If I every decided to sell it I would probably ask around $300 ,,, someone who keeps up with the Marble market ,,,,, should have a better estimate.