Complex sentence: The manuscript was purchased little before or around World War II by politician Lef Nosi, who was the owner of a remarkable personal library, and a notable collector, until it was confiscated from him by the communist regime in 1945.
Split into simpler sentences: The manuscript was purchased little before or around World War II by politician Lef Nosi, who was the owner of a remarkable personal library, and a notable collector. It was confiscated from him by the communist regime in 1945.