Complex sentence: During the 1950s it was still primarily the different sections, associations and unions of the labour movement that took lodgings in the house, even though all sorts of different activities took place; among others, these were boxing matches and end-of-season dances.
Split into simpler sentences: During the 1950s it was still primarily used by the different sections, associations and unions of the labour movement. All kinds of different activities took place: for example, boxing matches and end-of-season dances.