Bill,  I was recently able to obtain a copy of Bowers' book, 
"The Violin-Playing Machines: Hupfeld Phonoliszt-Violina Mills
Violano-Virtuoso A Study and Appreciation."

This book should surely answer most of your questions.  It was
published by AMICA in 2012.  ISBN: 978-0-9880116-0-1

Jim Quashnock