Complex sentence: For example, if by the late 1950s, our fictional "Fountain Green" had upgraded its manual service with an automatic (locally-dialable four-digit number) one, an operator could often dial the call after getting the routing.
Split into simpler sentences: For example, if by the late 1950s, our fictional Fountain Green had upgraded from its manual service to an automatic one, with locally-dialable four-digit numbers. An operator could often dial the call after getting the routing.