Early on the NID Field Grade didn't have the stars --
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.
In 1935, Ithaca dropped the cocking indicators, reprofiled the stocks and changed to the zig-zag border engraving.
Some of the post-WW-II Field Grades didn't get engraved at all --
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.