
Strowger 2000-type two-motion group selector
circa 1980
circa 1980
1985
1985
1979
1978
1978
1981-1983
1985
1986
1979
1985
1984
1982
1984
1984
1985
1984
1984
1984
1984
1984
1984
1985
1985
1984
1981-1982
1981
1979
1981
1984
1983
1985
2000-100 BCE
1982
1980-1985
1980
1979
1982
1983
circa 1983
1983
1984
1984
1980
1981
1979-1985
(1962); 1982
1979-1985
1981
1980