Thanks so much to all who recommended on-line articles. The FOPS
article is the one I had in mind, thanks to John Page for reminding me.
Interesting that the current scales made in the Cuban factory are 55
and 67 keys.  We have found that the 26-note scale can accommodate most
of the tunes we arrange for our Cuban customers.

The FOPS article URL has changed to http://www.fops.org/kf951tt.htm

We'll be adding some 78 RPM recordings of street organs from the 1920's
to our site's history page in a few days, in RealAudio format.  Any one
want to hazard a guess as to the organ makers?  As you will hear on one
example, the record's producers weren't terribly concerned with tuning!
Interesting to hear a blast from the past, at any rate.

All the best,

Brian Flora
http://www.floraco.com/organs/