I have reviewed the connections and rate setting in my GTE 120B payphone.
They are as follows:
On pin array B, the J6 connector is on ET.
On pin array A, the J5 connector is on ET
The rate selector is set to 35 cents, with switch "20", "10" and "5" set to on, switches "80" and "40' are set to off.
NOTE: The rate selector switch drawing is attached as a example only.
These are pretty neat phones; I like how they're easily configurable for a variety of different types of service and dial configurations. The setting of the two strapping arrays appears to allows the phone to be easily reconfigured for Semi-Postpay service, Traditional Pre-pay (coin deposit required for all calls Including "free" and emergency ones), or Emergency prepay (no coins required to call emergency services or operator).
The first letter of the label denotes type of service (P=Normal Prepay, S=Semi-Postpay, E=Emergency Prepay), and the second is for the type of dial (T=Touchtone, R=Rotary). So yours is configured for Emergency prepay with a touch calling unit.