Complex sentence: For the first 24 years, from the start of SKM service in January 1952 until December 1976, SKM trains used cars built in the 1930s for the Berlin S-Bahn and taken from Germany to Poland in 1945 as war reparations.
Split into simpler sentences: For the first 24 years, from the start of SKM service in January 1952 until December 1976, SKM trains used cars built in the 1930s for the Berlin S-Bahn. These cars had been taken from Germany to Poland in 1945 as war reparations.