All About Pocket Knives

Looking at some older threads is there anyway to tell if the year are (1917-1940's) or (1917-1987)

Goins lists the IKCO inside the rectangle mark as being used from 1925 - 1940 and the IKCO inside the diamond as being used from 1928 - 1930. Any Imperial made knife that has the construction shown on your knife with the handles pinned to the scales in the conventional fashion will be an older knife (there are probably some exceptions but this would be the general rule).

Thanks for the help