I used conveyor belt material instead of leather for suspending the
motor in this cow and calf Steinway.  You can buy this material from
McMaster-Carr.  Your upright should be similar.

You can see and hear the pump running on this page of my web site:
http://antiquemechanicalrestorations.com/Steinway_Duo-Art.html 
It is very quiet and moves a lot of air.  I'm sending other photos
to MMD to show the conveyor material used in holding the motor as
well as two additional straps.  One long strap holds the motor up
and a short strap holds it snug to the floor.

Paul Manganaro
newmatics@gmail.com.geentroep [delete ".geentroep" to reply]