Complex sentence: Car 5944 has been converted to R71 de-icer car RD340, while car 5871 (renumbered to 85871 and later 35871), formerly used for fire training, is being held for the New York Transit Museum.
Split into simpler sentences: Car 5944 has been converted to R71 de-icer car RD340. Meanwhile, 5871 (renumbered to 85871 and later 35871), formerly used for fire training, is being held for the New York Transit Museum.