RGSO22, I don't have Walt's excellant book by me right now and I cannot look up the exact serial numbers, but around 1925/1926 Ithaca started building the NID replacing its Flues model. If its a 12 gauge then it has 2 3/4 chambers. Like all American built shotguns NID's are built rock solid and tough, I have no worries about throwing modern loads through mine, But how do you know its an NID??
All the best