SOMETIMES a bit of detective work is in order to figure out a group of pictures.

This selection from our glass plate archive, purportedly "circa 1950s", came with a tag saying "batch 51".

Another slide before the next run of plates reads, "Previous pics 30s/40s? Focus Alliance?"

It is difficult to tell from these images if the pictures are from the 1930s, 40s or 50s, though our guess is early 1950s judging by the strip lighting and some of the office furniture.

Do you know any of the people pictured here? They are obviously carrying out clerical work.

A clue could be the word "Alliance" on that other slide. Could it refer to the Alliance Building Society?

The Brighton and Sussex Building Society was originally based in Brighton. Lord Lewis Cohen was its secretary in the 1920s and in 1944 it changed its name to Alliance.

The company moved into a three-storey steel-framed head office building at Hove Park, designed in the 1960s following a competition in 1956. With strong horizontal lines offset by granite columns and narrow windows, it was called a "great contribution to architectural thought" on its opening in 1967 but by the 1980s it was derided as a "carbuncle" and a "white elephant".

The merged Alliance & Leicester building society moved out in 1994. The building was later demolished.