Complex sentence: During the Second World War both were put in store and E1719E was rebuilt with larger panoramic windows for West Highland Line specials in 1959 by British Railways, but the other, numbered E1729E went into a long period of storage at Steamtown, Carnforth.
Split into simpler sentences: During the Second World War both were put in store and, in 1959, E1719E was rebuilt by British Railways with larger panoramic windows for West Highland Line specials. The other coach, numbered E1729E, went into a long period of storage at Steamtown, Carnforth.