Complex sentence: The first model was the SKC/28 used on the "Deutschland" class, the "Scharnhorst" class received a longer barreled version-the SKC/34.
Split into simpler sentences: The first model was the SKC/28 used on the "Deutschland" class. The "Scharnhorst" class received an improved version of the SKC/28 which had a longer barrel--the SKC/34.