This is the plastic coupling that sits behind the ignition barrel in the switchbox. It is recommended that you keep a spare on hand at all times.  1990 from VIN 30001 onward

This is the ignition rotor for single point distributors. 1969-1980 Silver Shadow, Shadow II, T-1, T-2, Silver Wraith, Corniche (8742-41686) 1980-1990 Silver Spirit, Silver Spur, Mulsanne, Eight...

This is a complete set of ignition wires / HT leads / spark plug wires.  This set includes 9 leads / wires. From 1969 VIN 8742 to 1987 VIN 16970  

Voltage Regulator found in the trunk of the car. 1977-1980 Shadow II, T-2, Silver Wraith II (from VIN 30000 onward) 1981-1983 Spirit, Spur, Mulsanne, Corniche (up to approx VIN 9533)