[ Ref. Steffen Just in 230322 MMDigest ]

Lots of interesting history and anecdotes about piano roll
perforators and related machinery appear in the long article,
"Don Rand Telephone Interview," published in The AMICA
Bulletin, July/August 1995, Volume 32, Number 4, archived at https://stacks.stanford.edu/file/druid:hj658hs6094/32-04.pdf 

Robbie Rhodes - Mechanical Music Digest