Circa 1915 the engraving patterns were changed on several of the Ithaca Flues models. The one of interest here is combining the Quality 1 and 1 1/2 into one gun--the Quality 1 that the OP shows. There were manufacturing changes also. The one that comes to mind is the barrel lug.
Cody does have the NID records and will do letters. I still have the Mag. 10 records that I will be sending soon. I do not do letters.