Information on other vintage electro-mechanical telephone switching of note.
North Electric CX-100 All Relay Switch
An all-relay central office is somewhat of a hybrid of a step-by-step and a crossbar office that used mechanical relays instead of crossbars or mechanical wipers. These switches only used for very small central offices. One company of note who made all-relay central office switches was North Electric of Gallion, Ohio (again, not to be confused with Northern Electric of Canada). The CX-100 and CX-1000 (100 and 1000 subscribers respectively) models were used in a limited degree in the public network.
North Electric CX-100 switch at the Connections Museum Seattle, WA
Vintage Telephone Switching Systems Index
Step by Step (Strowger) Switching Systems
Western Electric Panel Switching Systems
Western Electric Crossbar Switching Systems
North Electric Crossbar Switching Systems
Other Vintage Switching Systems of Note
Telephone Switching Systems of North America