Earliest Coro mark, registered in 1921

Alternative mark, used until 1941 or 1942

Used first in 1929; registered in 1930

First used in 1935; registered in 1937

Often used in combination with the mark "Sterling" after it.  Do not know dates used. Can anyone help?

First used in 1942, and in use until 1944

1942 - 1944

1942 - 1945

First used in 1944; registered 1945

Used to 1947

First used in 1940 or 1941;

use ended in 1948

Registered 1956?

Used to 19??