Complex sentence: For the attack 3rd batallion (the regiment's right flank) was reinforced with two guns from the division's artillery, 85th Artillery Regiment, a company of engineers and an 88 mm Flak gun.
Split into simpler sentences: For the attack 3rd batallion (the regiment's right flank) was reinforced with two guns from the division's artillery, 85. Artillerie-Regiment, a company of engineers and an 88 mm Flak gun.