After reading Todd Augsburger's inquiry about the Concert Roller Organ
with external relief valve, I took a look at my Concert Roller Organ
and find that it has an external relief valve.  I would be glad to help
him out, just let me know what you need.  Perhaps digital photographs
would be the way to go, with a ruler in the photos to provide size and
proportion.

Marvin Polan
Long Island, N.Y.