Yesterday I got my perforator functioning and I have already cut
a bunch of rolls with it. Here are some observations:

1. The paper feeding isn't bad so long as the perforator doesn't have
to make cuts on the back stroke. If it cuts a hole that's very long,
it'll return to where it started and alignment will be fine. So the
moral of the story is, you can leave note slots un-bridged and they
can be quite long. However, edge trims should be only _10 rows long._
Edge trims were _very_ problematic for me when I did the first test
cuts and shortening them pretty much solved every issue I was having.

2. Unless the paper guides are set correctly and the paper advance
isn't causing any twisting motions (which is not the case for me!),
the paper will wander a bit back and forth. However, it is not even
close to being enough wander to be problematic; my Aeolian with
a dead tracking pneumatic can play most of the rolls just fine as
long as I make sure they're wound straight on the spool. A piano
with a functioning tracking pneumatic -- or even better, a mechanical
clutch-based 'fishing pole' tracker system -- will track flawlessly.

3. Yes, I'm doing custom roll cutting, just drop me an email: 15 bucks
per roll with no shipping included. I'm using QRS roll parts so the
spool flanges have QRS stamped into them. The end tabs are also from
QRS. The paper is brown 30-pound kraft paper and it works perfectly.

All the rolls are test-played on my unreliable Aeolian so if they can
play on that piano  then they can most certainly played on one that
actually works well. I can cut just about anything that is a MIDI file,
even orchestral MIDIs for all that's worth; I'm dead serious about
that, too.

Also, Bill Luecht has the drop-in version of the perforator and he's
a wizard when it comes to the setup. If you want to build one, build
the drop-in version according to Spencer's documentation and then go
to Bill for all the other fun stuff you can do to make the perforator
absolutely bullet proof. Julian Dyer and myself are the guys to go to
when you have questions about mastering rolls and turning them into
Gcode.

Piotr Barcz 
Upstate New York