Complex sentence: Construction of the facility commenced in late 1942 at a cost of £30,579 with its official commissioning in January of 1945 as the headquarters for No.1 Fighter Sector RAAF.
Split into simpler sentences: Construction of the facility commenced in late 1942 at a cost of £30,579. Its official commissioning was in January 1945 as the headquarters for No.1 Fighter Sector RAAF.