I started taking the screws out of the bar holder and messed up. The screws won't back out. So, I've removed the whole assembly and ordered new chord bar holders. What a start....
   At least now I see just what's what and I've slowly marked the chord bars to know where to cut the new felt. Instead of matchbooks or similar, maybe I'll cut the felt a teeny bit long on both sides to slightly snug it to the end where it meets the casement. I've scrounged up rubber bands for the tops of the bars and have some very thin felt that might work also.