Tim, I can email you a diagram that was used as a training aid in NYTelCO Plant Training School. It shows a 701A PBX, diagramming one call through the switch train. One LF, one SEL, and one CONN, along with the L&CO and group relays and ringing plant. You will, in turn, need to email it to a commercial printer who has the capability of printing on a 2 foot by 3 foot piece of paper.
