Early on the NID Field Grade didn't have the stars --

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Sometime during 1927, the boys & girls in the factory began putting the stars on the Field Grade NID, but the folks in the office didn't add the stars to the catalog pictures until 1929.

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In 1935, Ithaca dropped the cocking indicators, reprofiled the stocks and changed to the zig-zag border engraving.

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Some of the post-WW-II Field Grades didn't get engraved at all --

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NID 20-gauges were made for 2 3/4-inch shells from the get-go, but they only marked chamber lengths on the very late guns.