Lihpster, you are very kind to offer up a part of yourself - your Dad - to the people of the forum. A wonderful gift contains something of the giver and something of the receiver. Your gift of the knife and grips tags both bases. Nicely done!
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?