Hi All,  I went to the Music Trade Review (MTR) file I have and got
this image of the roll using the capture feature in Adobe.  I set
the magnification to 1600.  The marks on the roll are much clearer.
I won't speculate about what can be seen.  It's just a much better
image...

Also, there's a web page at Player-Care about the Welte-Mignon
recording process as explained by Dr. Ludwig Peetz.  See
https://www.player-care.com/welte-recording.html 

Musically,

John A Tuttle
Player-Care

 [ Welte-Mignon (Licensee) Master-Roll
 [ http://www.mmdigest.com/Attachments/19/08/24/190824_111211_welte-recording-process-3.jpg