This is the thermostat for the early cars with the 6 Cylinder engines.  Opens at 78 degrees. 1946-1955 Mk-6, R-type, Silver Dawn, Silver Wraith  1956-1959 Silver Cloud I & S-series 1...

This is a used thermostat housing with the outlet for the top hose. 1955-1959  Silver Cloud I and S-1  (6 cylinder Only) This photo is for reference only and the par

This is the square gasket between the rear of the thermostat housing and the front of the cylinder head. Rolls-Royce Silver Cloud I & Bentley S1