Mastering piano rolls from MIDI files

I mentioned in a previous post that ScanImage MIDIs are needed to make
perfect piano roll copies to the punch row (with a couple errors here
and there, sometimes you'll get one punch on a chord that is incorrect)
however I've found that you can use eRoll MIDIs the same way.

I now believe that any eRoll or ScanImageMIDI can be mastered by simply
scaling it to 24 ticks per row in [Julian Dyer's] Perforation Editor.
ScanImageMIDIs are the ideal medium because they often include
reproducing dynamic coding in the form of notes off the 88-note scale,
whereas eRolls are emulated and don't have that. But otherwise they
are identical and can be used to make recuts (albeit, as I mentioned,
with a few tiny errors, the best source is always a high quality
scanimageMIDI).

For those who have 88-note players with no expression system, recuts
made from eRolls and not ScanimageMIDIs of reproducing rolls will be
more than adequate, I'd say.

I'd just like to point out that scans made by Terry Smythe and Peter
Phillips won't work as they don't use a set scaling, as far as I can
tell. However, scans by pretty much everyone else will work (Mike
Swanson's and Marshall Jose's scans are probably the best material
overall).

Ah, and you may be wondering how I was able to confirm this processing
method works. Piano roll scans made with Warren Trachtman's methods
have a MIDI tempo the same as the roll tempo. In Perforation Editor,
after converting the scan to PunchMIDI, the roll tempo is set
automatically and the music speed matched the MIDI.

Piotr Barcz
Upstate New York