PPCo Vacuum Pump Speed Controller Diagram -- by John A. Tuttle
Lauter-Humana Layout Diagram & Poker Tool -- by John A. Tuttle
Aeolian Themodist Schematic Diagram -- by Richard Vance
Mignon 22-note Reed Organette -- by Hans van Oost
Duo-Art Tubing Diagram, 1925 Steinway Duo-Art Grand Piano -- courtesy Eliyahu Shahar
Duo-Art Piano Concertola -- courtesy Jim Heyworth