Now I have a question for you, having gone back to look at the initial photo. Your Dad's knife has 3 notches; two on one side, one on the other. Do you know and care to share the meaning of the notches?
Actually, it's just a bit of decorative filework. If you turned the knife over you would see that the opposite side has the opposite number of notches. The notches alternate sides and there was only room for 3, so when you see the one notch, it's in the middle position. When you see 2 notches they're in the first and last position.