Rod Rogers asked about his Howard roll frame gears.  I believe his
piano has a Monarch roll frame and pump; see the "Encyclopedia of
Automatic Musical Instruments," top of page 709.

I've encountered the same roll frame in Tangley calliopes I've
restored. See the photos of the roll frame gears toward the bottom of
the page: http://antiquemechanicalrestorations.com/Tangley_Calliope.html 
Al Meekins, of Meekins Music Box Co., in Collingswood, New Jersey,
made the replacement gears for this project:  http://gearsmade.com/ 

I remember the [original] gears were good in at least one of the others
I worked on.  Al charged about a thousand dollars for all the roll frame
gears several years ago.  The compound gear with one straight and one
bevel gear together looks like quite a challenge to cut.  If anyone knows
a better source I'd like to know for next time.

Paul Manganaro

 [ I asked an antique auto restorer about replicating gear sets.  He
 [ said most of the expense is the cost of programming the numerical
 [ control (NC) milling machine, and the customer can save money if he
 [ will help gather the dimensions and tooth profiles.  -- Robbie