Hi,  I want to state from the onset that I have no financial connection
with McMaster-Carr but had to sing their praises for a good tool they
offer.  And maybe this tool isn't news to those that have been at this
a long time.

It is part number 1848 K1, price $70.34, "Joining Tool" for leather
round belting.  It may be a little pricey, but I was able to cut the
belt to length, punch the holes for the wire staple and crimp the
staple all without having to remove the belt from the piano.  The motor
pulley and driven pulleys for the original Welte Mignon are all located
next to the strings, on the less accessible side, so I thought it was
going to be a difficult job.

McMaster-Carr also offer more sizes of round leather belting than you
can shake a stick at, and at very reasonable prices.

I hope someone finds this useful.

Bob Hodge

 [ See the tool at http://www.mcmaster.com/#catalog/119/1043/=pjiiwm 
 [ -- Robbie