A belated welcome
I was at King Alfred School Ploen,the BFES Secondary Boarding School, some 20 miles east of Neumunster, in the mid 50s. There were a number of pupils from Neumunster whose father's were serving with the Armoured Car Regiment stationed there so there must have been a BFES primary school in the town but whether it was in a requisitioned building or a converted barrack block has never been established on this site. We do have a couple of contributors who were stationed in Neumunster, they might be able to give you an answer when they next drop in.
Think your father must have been based in Headquarters Hamburg District which was located in one of the suburbs to the west of Hamburg city centre. We had a query a few years ago from someone who was at primary school in Hamburg in the mid 50s, buried in the site's archives is the detail but s I recall it was in a requisitioned building in the Blankenese area.