A brand new ( Lockheed design) 1″ bore brake master cylinder as fitted to the following pre-war Morris models , 1936 – 1939 10/4 Series II & III….Morris 12/4 Series II 1936 – to mid 1938…….. This cylinder will not fit the Morris 10 series ‘M’ mid 1938 – 1947 or the 12/4 series III – from mid 1938 – 1939…………. The equivalent OE Lockheed part number for reference was 14896. Casting number 993 12184.
Note 1/2 inch UNF outlet.
Over the years its possible your car had an earlier or later M/C fitted, in some cases the only difference was the thread of the output! Its worth checking from the diagram below (extracts from the Lockheed Catalogue) that you are ordering he correct model.