Thanks to people who responded to my question.  Robbie Rhodes,
George Cooper, Nathan Woodhull, and Gordon Ramsey have given good
input.  Something that I noticed after sending my first request was
when I compared the gear configuration between the MMD picture and
an older picture of the MIM [Musical Instrument Museum] spool frame,
the MIM frame has gearing that makes the rewind speed two times faster
using the same motor that is on the MMD picture.  This means there is
one-half the torque for rewind.  Here are pictures comparing the two
frames.

 [ 2004 Roll Frame picture from MMD (both gears same diameter)
 [ http://www.mmdigest.com/Attachments/14/02/21/140221_090027_MMD2004Roll-Frame.jpg
 

 [ MIM Roll Frame with a larger gear on motor.
 [ http://www.mmdigest.com/Attachments/14/02/21/140221_090027_MIM%20Roll-Frame.JPG
 

Some of the suggestions indicate the roll frame was never built for
15-song rolls, which I agree with.  But this frame has also had
problems rewinding with the 10-song rolls so I want to guarantee it
will always rewind.

There are two methods I can use to increase the torque; both methods
mean replacing the gear-motor.  One motor has twice the torque but
two times the RPM (1MBG6).  The other motor has one-half the speed
but two times the torque (1MBF9).  At this time I think I will try the
slower speed method only because then the rewind speed will be almost
identical to the original old roll frame as pictured back in 2004.
It should also have the same drag characteristics when it play mode.

It was brought to my attention that the frame may provide a small
current through the rewind motor to add extra drag to the roll.
I will have to check this out later.  And there will also be extra
drag just because of the gearing change.  Will check this out and see
if we can live with this.  If not, then I go to plan B with the 1MBG6
motor.  Will report back about my findings when everything is complete
and working.  Any other concerns are surely welcome.

Pete Knobloch
Tempe, Arizona