1930s
1940s
1980s
Nickel, Richard
1960s
Korling, Torkel
1950s
Purrington, Frank L.
after 1956
Hedrich-Blessing
Helmick, William K.
circa 1950
Mackay, Edward J.
1977 – 1978
1973 – 1992
Hart, Nancy
January 25 1978
1935