This photo is noted to the reverse 'July 1948, Josephine'. Josephine would have been nearly new July 1948 and she is an Ariel twin port NH350.
Twin exhaust ports were all the rage pre-war but decidedly old hat post. The only two British manufacturers I can think of who made twin port machines after the war were Ariel and Royal Enfield with their J2.
|Josephine is an Ariel NH350.|