felt, by the way, is one of the favorite menu items
for carpet beetles, a.k.a. bow hair bugs. these critters
(in the larval stage) love munching on animal products--
fur, feathers, hair, carpet, wool, felt, leather, etc.
their little caracsses might be evident in places where
they have shed their "skins". They are found here;
http://ohioline.osu.edu/hyg-fact/2000/2103.html and here:
http://www.ext.vt.edu/departments/entomology/factsheets/carpbeet.html

I was at an autoharp workshop with bryon bowers once and
he recommended extending the life of felt bars by running
a layer of shoe goo, silicone seal, or barge cement over
the surface. This also serves to take up the slack in the
harp allowing quicker chord changes, sue to less travel
distance the button has to go with each chord.(of course you
don't play until it is absolutely dry!)