ITR and IBM Master clock documents

ITR catalog
ITR regulating system
Instructions, style A master clock
ITR Price sheet
ITR service 222, 1938
ITR service 222, 1958
ITR Model 25 parts

Master clock parts list
Synced secondary clocks
Impulse secondary clocks
Self regulated secondary clocks
Tower clocks
Special secondary clocks
Secondary clock movements
Signal devices

12 hour impulse accumulator

Thanks to Harvey Schmidt for many of these documents.