I posted this query on a theatre organ Facebook page.  Several
Robert Morton organs installed in Detroit (Annex and Tuxedo) had
V'Oleon (correct spelling) units installed.  They were fairly
useless, hard to keep in tune, and so quiet as to be useless in
any ensemble or in a large theatre.  No one provided information
on where one might be in use today.

More information and some good photos may be found in David
Junchen's "Encyclopedia of the American Theatre Organ (OOP)" and
on Greg Rister's excellent Robert Morton website, at the bottom of
page  http://www.robertmorton.org/construction-protocols.html 

David C. Kelzenberg
Iowa City, Iowa
david-kelzenberg@uiowa.edu.geentroep [delete ".geentroep" to reply]

 [ See also the MMD article by Bob Loesch at
 [ http://www.mmdigest.com/Archives/Digests/200109/2001.09.11.01.html 
 [ -- Robbie