Brunsviga mechanical calculator

From: Sarah
Email: sarahlduncan@yahoo.com


My mother has asked me to see what I could find out about a mechanical calculator she has that belonged to her father. It is marked Brunsviga Midget System Trinks and has patent dates of June 12,1906 and January 11, 1910. Any idea of value? Thank you! I'm going to look at the book by Thomas Russo.