Spencer Chase,  I was rereading your advice of about a month ago, and
thought I'd comment on my experiences:

Recently, I overhauled a Rolmonica and found exactly the things you
commented about, with the addition of a warped wood core.  I filed the
"high" side and filled the low side with a sealer in order to get it
airtight.  The brads that hold it together were loosening in a couple of
places, so I relocated the angle of them upon reinstallation.  It is
easiest to "slide" them into place with pliers rather than "nailing" them
in.

Regarding the "leathers": After some experimentation, I ended up using
leather strips tacked with cyanoacrylate glue on BOTH ends.  The leather
is flexible enough to bow out in the middle when opening, but is held
into place so as to immediately and easily close upon change of the
inhale/exhale cycle.  This made a *noticeable* improvement in ease of
blowing, and also appeared to aid the inhale cycle somewhat.  I would
guess that the original is a poor design for valves.

But even when the air movement seems good, the inhaling sound quality
still is poorer quality than exhaling--Anybody know why? Is it the way
the channels are designed with the reeds on the opposite sides? Is this
different than a regular harmonica?

And yes, the arrangements of music left something to be desired.  But I'd
like to buy some more, if anybody has some for sale.  Does anyone make
NEW rolls?

Todd Augsburger