1980 280 E fuel pump relay

hi, i recently purchased a 1980 280 E but the fuel pump relay is shot (so i was told by the previous owner). the car works after pouring some gas down the throat but stops abruptly after that is used up. what i want to know is how to bridge the terminals to get the pump to work. even the Haynes manual seems wrong in their circuit diagram relative to the markings on the relay.
please tell me which terminals to bridge and where to find the safety switch that is supposed to be connected to the 'air plate' that stops the pump if the car does not start; also, it seems to have a cruise control vacuum bell but no sign of cruise control on the inside of the car, where would it be located? this is my first Mercedes.
Much thanks,
Mr P