This is a good used by pass elbow that is on top of the water pump volute casing for the S shaped tube UE37117.  You will also need the gasket RH12756 that seals the elbow to the casing...

This is the 'S' shaped by pass tube. You will need 2 of part# UE9333 to make a complete fit 1974 (VIN 18418 to 41686) 1981 to 1986 (up to VIN 16970)

This is the larger diameter o ring that sits between the coolant pipes and the thermostat housing on all cars from 1987 onwards (VIN 20001). 1981-1998  Silver Spirit, Silver Spur, Mulsanne,...

This is an (original part) coolant temperature sender.    1977-1980 VIN 30001-41686 1980-1998 From VIN 1001 onwards