Complex sentence: With only 60 C-97 transports built the designs did not meet much success as a transport however, the design proved to be highly successful in the guise of the KC-97 Stratotanker flight-refueling tanker.
Split into simpler sentences: With only 60 C-97 transports built the designs did not meet much success as a transport. However, the design proved to be highly successful in the guise of the KC-97 Stratotanker flight-refueling tanker.