Serial number range: 2682801-3009650 (1974-1979, approx. 2,950 produced). Production by year: 1974: #2682801-2683000 (200 units); 1975: #2755051-2755350 (300 units); 1976: #2768901-2769200 (300 units); 1977: #2816851-2817350 (500 units); 1978: #2907801-2908100 (300 units); 1979: #2990301-3009650 (1,350 units).