Complex sentence: Production was suspended during World War I and when the car re-appeared in 1919 the engine was enlarged to 1224 cc and the price had risen to £400 then to £500 which was too expensive and sales dried up after a few hundred had been made.
Split into simpler sentences: Production was suspended during World War I and when the car re-appeared in 1919 the engine was enlarged to 1224 cc and the price had risen to £400 then to £500. This proved to be too expensive and sales dried up after a few hundred had been made.