Rear Wheel Brake Cylinder - Rear Drum Brakes -  Lockheed  Triumph TR7 5 Speed & Ford Escort MK1 RS1600 & Mexico 1.6  BBW1066
Rear Drum Brakes - Rear Wheel Cylinder  Triumph TR7  5 Speed  BBW1066
You would normally replace these units in pairs 

As found on :
Triumph TR7   Rear Drum Brakes -  5 Speed and Automatic Transmission  from VIN 402001
Ford Escort Mk1 RS1600         (Jan 73 - Jan 75)    Lockheed Brakes Only
Ford Escort Mk1 Mexico 1.6   (Jan 73 - Jan 75)    Lockheed Brakes Only 
 
GWC1212
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