I have two Seeburg nickelodeons in my collection right now.  One is
a Model "L" and the other a "G", and until recently I had a KT Special.
All had factory installed rewind methods!

On the model "L" (mine and two more I am familiar with) there is a push
button located on the bottom board of the spool box.  On the Model "G"
and the KT Special there is a push button hidden neatly just behind the
tracker bar, on the bass end.  In all cases, this push button (finger
valve) is simply teed into the line from the rewind port of the tracker
bar that goes to the rewind pneumatic.

I can't imagine that Seeburg only equipped their smallest and second
largest coin pianos with this feature and models in between would not
have it.  Is it possible that this feature had been removed prior to
the current rebuild?  It is a very simple device to build from scrap
parts.

Easter Greetings to all --
Ken Vinen
Aylmer, Ontario, Canada