Looks like they sell the buttons but I’ll need to inquire about installing instructions.. I also have a question about knew bones. Are they fairly generic in terms of fit or do should I check with the harp maker for a recommendation? thanks Frank
Frank each harp varies in its centre of gravity so it would be best that you get instructions for the particular instrument you have.
I use a musicmakers knee bone for one of their lap harps and highly recommend them. I am not familiar with the design of your harp but I imagine the knee bone could be used in a wide variety of harps and would not be difficult to modify (by you) if you required that.