Approximate Keilwerth Serial Numbers:

1925: 0-800 

1947: 20,000

1953: 23,000

1958: 28,000

1960: 38,000

1962: 43,000

1964: 49,000

1966:  55,000

1971: 69,000

1978: 79,000

1986: 91,000

1993. 99,100

1998:  109,000