Bless you for sharing that. Yes, Sharpie comes off with alcohol...or with wear in the field. I hope your grandfather travels many happy trails with you, before the name wears off the bows. After that, he will ride in your heart, and keep it young.
My mother was a potter, and made many items of practical daily use. She died in 1983, and I am still using her dishes, bowls and planters. As time goes on, time takes its toll and they chip, crack, break...and for a while that made me sad each time it happened, as if she were getting 'deader'. I have since grown a little, and realize that as these things fade from this world, as she did and I will, her memory is still alive and burning in my heart. I have her teachings, a bit of her handwriting style, and sometimes, her sneeze. She will always be with me, even after the last bowl breaks. So it will be with your bows. Remember well all that your grandfather taught you, and ponder lessons that perhaps you did not know were lessons. You will find yourself understanding them as you grow old. The way a person lives a life is perhaps the greatest lesson of all.
Killdeer