"One trick I learned to keep the bars from clacking when you're playing quickly is to get some of those little green felt pads that you put on the bottoms of vases, cut them in half and (after removing the two screws each and the bar covers) put one on each end of the bar. You'll never hear a sound out them, just pure harp."
This is a great idea but certainly not a new one. We own an 1898 Dolgeville Model 73 (12 bar) and the bottom sides of the bar covers have a thin piece of felt glued on. Does a great job of quieting the bars.
Bev and Jerry