Ithacas, like Parkers, were boxlock design- in the hammerless series-- a bit of a misnomer, as all firearm have hammers, but a "hammerless" means the hammers are inside the receiver.
The Ithaca red recoil pad is NOT a 100% clue- as I have seen several non-Ithaca shotguns wearing a Ithaca red sunburst recoil pad.
Brother Carr is 100% correct- if you can post pictures and list all numbers and letters from the receiver and barrel flats, etc- maybe we can be of more help in I.D. ing your .410 double
