Complex sentence: The 3½ Litre (and later 4¼ Litre) was presented to the public in September 1933, shortly after the death of Henry Royce, and was the first new Bentley model following Rolls-Royce's acqisition of the Bentley brand in 1931.
Split into simpler sentences: The 3½ Litre (and later 4¼ Litre) was the first Bentley to be developed by new owner Rolls-Royce. The Bentley 3½ Litre was presented to the public in September 1933, shortly after the death of Henry Royce, and was the first new Bentley model following Rolls-Royce's acqisition of the Bentley brand in 1931.