Simplify the following text for a Grade 10 native English-speaking person.
Original: The Metropolitan Cammell Carriage and Wagon Company ( MCCW ) was a Birmingham , England based manufacturer of railway carriages and wagons , based in Saltley and subsequently Washwood Heath .
Simplified: The Metropolitan Cammell Carriage and Wagon Company ( MCCW ) was a manufacturer of railway carriages and wagons . They were based in Saltley - and later Washwood Heath - in Birmingham , England .