Which REAR Brake Cylinder Should I Use ?

[62Countryman]

I have a 62 Austin Countryman (Registered in Jan 1962). The title says Austin Seven Countryman. One of my rear cylinders is leaking therefore I wanted to replace both rear cylinders while I am working on the car. The car has single leading shoes for the front brakes. I am not sure what the bore size is (Brake Reservoir). Are the rear brake cylinders different on a 1961? The reason that I ask is because it looks like most of the parts on my car are from 1961 even though my car was registered in early 62? What part number should I order? Does anyone have Lockheed parts for sale or I will I have to buy aftermarket parts?

[IAIN]

I think that you car would be the early cylinder but it depends what back plate is fitted on the car now. The locating pin on the cylinders are on different sides of the brake pipe.
Personaly I wouldn't worry about the bore size.