The Lionel Transformer Type 1043 was available from 1953 until 1958. It would control one train. It does not have a built-in circuit breaker, but after 1957 Lionel would offer the No. 91 Circuit Breaker that could be used with this transformer. There are three variations:
Variation A: Produced 50 Watts of power and came in a BLACK case. 1953-57 Production
Variation B: Produced 60 Watts of power and came in a BLACK case. Note that this variation came in a box that was marked at 50 watts. 1958 Production.
Variation C: Produced 60 Watts of power and came in an IVORY case that has GOLD plated speed control and terminal binding nuts. Came in a box that was numbered "1043-500." See No. 1043-500 in 1957 and 1958.