I've recently discovered that MuseScore can detect tempo from an off
tempo MIDI file (like piano roll scans). I've made sheet music from
some files and, I have to say, it came out better than what could have
been made.

If anyone wants to access the sheet music or MIDI then please email me
or go to my homepage on musescore.com where, with a free account, you
can download a few scores I've made from piano rolls.

Since the rolls can be quantified, this makes _perfect_ roll replicating
possible. You can use a MIDI editing DAW [digital audio workstation]
to extend notes to reproduce drones and trills or whatever is needed.

MuseScore creates MIDI files that have 480 ticks per quarter note.
If it is desired to use Julian Dyer's perforation editor then 12 ticks
per punch row is the value I have found to work well.

I can only create sheet music from very evenly played piano roll scans
without any serious unevenness in tempo or notes. If the roll has swing
then I can even that out, up to a point -- this will ruin triplets that
I will have to add myself later on.

I've attached some MIDI files that I have edited.

1. This was tricky to do but I managed to make a decent MIDI from a very
complicated arrangement by J L Cook.

https://www.mmdigest.com/Attachments/20/11/25/201125_174836_Here%20Comes%20The%20Navy%20(Roll%20Out%20The%20Barrell)%207780S%20(quantized).mid 

2. My best sounding arrangement that can be barely told apart from the
original. There is one botched grace note and the tenth drones are
retracted.

https://www.mmdigest.com/Attachments/20/11/25/201125_174836_Hey,%20Good%20Lookin'%20(What%20ya%20got%20cookin').mid 

3. Sheet music for Hey, Good Lookin'

https://www.mmdigest.com/Attachments/20/11/25/201125_174836_Hey,%20Good%20Lookin'%20(What%20ya%20got%20cookin').pdf 

Piotr Barcz