Complex sentence: The L-1049 had some 550 improvements and modifications compared to the L-749, including increased fuel capacity, rectangular portholes, larger cockpit windshields and improved heating and pressurization.
Split into simpler sentences: The L-1049 had almost 550 improvements and modifications compared to the L-749. Improvements over the L-749 included increased fuel capacity, rectangular portholes, larger cockpit windshields and improved heating and pressurization.