Serial number range: 2046001-3470570 (1964-1988, approx. 21,600 produced). Production by year: 1964: #2046001-2047000 (1,000 units); 1965: #2105801-2145450 (3,000 units); 1966: #2188901-2213000 (4,500 units); 1967: #2231801-2233800 (2,000 units); 1969: #2382701-2384700 (2,000 units); 1970: #2420201-2459500 (3,000 units); 1971: #2481101-2482200 (1,100 units); 1972: #2549551-2550550 (1,000 units); 1975: #2755351-2756350 (1,000 units); 1978: #2906801-2907800 (1,000 units); 1986: #3414891-3415890 (1,000 units); 1988: #3469571-3470570 (1,000 units).