Here's a new Brake Master Cylinder (3/4") for the following models from Austin -

AUSTIN

Austin A55  (Van / Pickup Version)  (1957- 62)

Austin A60  (Van / Pickup Version)  (1962- 73)

(** From 1962 onwards the Van or pickup version is badged as an Austin A60 even though it's still the A55 shape **).

(** Not for the A60 Saloon which uses a different bore **)

(You'll need to re-use your old rod, it's an easy swap as it's only held on by a circlip).