Complex sentence: The base had been inaugurated, but scaled down to a maintenance status with a public works office in 1944; from that moment on and until 1957, the base went through many shifts, being opened seven times and closed eight times.
Split into simpler sentences: The base had been inaugurated, but scaled down to maintenance status with a public works office in 1944. From then until 1957, the base went through many shifts, being opened seven times and closed eight times.