Serial number range: 920000-2887150 (1951-1978, approx. 276,980 produced). Production by year: 1951: #920000-930000 (10,001 units); 1952: #959001-1045000 (15,000 units); 1953: #1091001-1119000 (14,000 units); 1954: #1124701-1236000 (39,200 units); 1955: #1252001-1330000 (27,800 units); ... ; 1973: #2583501-2656950 (4,050 units); 1974: #2698501-2698600 (100 units); 1975: #2731922-2757350 (1,029 units); 1976: #2794651-2796150 (1,500 units); 1978: #2887001-2887150 (150 units)