Pat DeWitt,  Congratulations on your recent acquisition of a roller
organ.  Regarding the "noisy valves", I suppose it's not that unusual
if the felt/leather is old and stiff.  I've seen some which are nearly
rigid!  The valve pads are easily replaced, so it would be worth doing
if that's the case.  I have also been experimenting with a closed-cell
foam which seems to work well.  Let me know if you wish more information
on that option.

The left/right adjustment screws will reposition the carriage, but
_not_ the roller (cob), which it is laterally positioned by the worm
gear, as it moves from left to right.  Therefore the screws should be
adjusted to allow the worm gear to travel fully, and the carriage to
pivot freely without slop, but it's not very critical.

There is usually no adjustment necessary to the worm gear; it's either
crimped or soldered in place.  If individual valve pallet teeth do not
align to the pins on the roller, they may be adjusted by bending the
teeth gently.  Also, do make sure that the metal ferrule is correctly
seated in the rollers--it is possible for them to work loose.

Values are hard to establish, since I've seen Gem Roller Organs sell
from $200 to well over $1000 depending on condition and number of
rollers.  I'd say an average is about $550 for a Gem in good working
(or restored) condition.  Rollers sell from $15 to $25 these days,
on the average.

I maintain a Buy/Sell/Trade page at my web site where there are several
listed at $15 each, from several persons.  You'll also find various
other background information, repair sources, a discussion of Roller
labels, and a nearly complete list of Roller Titles.  See my web site
http://www.bright.net/~allmax/index.htm and go from there.

Enjoy!

Todd Augsburger