To the Original Poster here, you did ask a pretty darn tough and hypothetical question... and your snapping at people and passive aggressive responses ("I hope this clarifies what it means to be helpful" for instance) are not going to make people want to help you with this...
You will get more flies with honey than vinegar as the saying goes.
As to what you can do for these hypothetical knives and grandkids, I have no clue. I have seen purpleheart used in some bows, and it is pretty but I dont know what kind of finish you would use on it. Try calling up a maker of traditional bows, like Bear Archery or Black Widow bows, and ask them what they use with Purpleheart. They would be the experts to talk to. Truthfully, any natural material will age and change, and that is part of the beauty of them. Good luck, and I hope your knives and your future progeny turn out wonderful!
