Southampton Fire Brigade post ww2 formed in 1948 when the N.F.S ( National Fire Service 1941 to 1947 ) handed back fire control to regional county & county borough fire brigades. Southampton Fire Brigade, a small county borough fire brigade in Hampshire, had 3 fire stations covering 15 square miles of the Southampton area. The badge changed in 1964 when the brigade changed its name & badge to Southampton City Fire Brigade, putting this cap as pre 1964.
In very nice original condition, this Southampton Fire Brigade dress cap from the late 1940's / early 1950's period has the original issue badge.  Looking at the rear lugs that can be seen ( see photo close up ), the badge is the 1st issue with brass showing through the crome  lugs to the rear, where the split pin attaches the badge to the hat.