The high grade Flues double shown on the order form in the Flues era Ithaca Gun Co. catalogs from 1919 thru 1925 has a Jostam Anti-Flinch pad.
The gun on the order form in the 1915 Ithaca Gun Co. catalog has a butt plate.
Looking through a bunch of my old catalogs I find the Hawkins pad shown in the 1926 E.K. Tryon catalog. No Hawkins pad in the 1922 Schoverling, Daly & Gales catalog. I have several undated H & D Folsom catalogs and the ones that have the Flues Model Ithaca doubles have no Hawkins pad but when the NID appears the Hawkins pad is on the recoil pad page.