By 1979, a Deluxe Grade at $549.95 and a Supreme Grade at $649.95 were available. The gun was only available with a full-choke 52-inch barrel. “The Ithaca Gun Company From the Beginning” by Walter Claude Snyder.The Ithaca Mag-10 was designed by James Tollinger & introduced in 1974 at a cost of $424.95. This strategy was implemented in the early months of 1916 with the purchase of the Lefever Arms Company in Syracuse, New York. The strategy they chose for accomplishing both objectives was to purchase a well-known and respected gun company, discontinue its products, and introduce their lower-priced line under that firm’s name. However, they did not want to degrade the price-quality image enjoyed by the long-established Ithaca Double. In fact there is a fairly nice original Flues 12 gauge for sale now for $300.00.Ithaca Gun REFERENCE CENTER click photo to get schematic & parts list.On the eve of World War I, the management of the Ithaca Gun Company decided to develop and market a lower-priced line of shotguns. A gun in the condition of yours would not bring more than $150.00 where I am. As far as value, these guns aren't worth that much. These guns are vintage guns and are fun to shoot (if safe) and should be treated with respect to their age. Heavy loads will likely crack the stock in the wrist area. One also has to remember that the wood is nearly 100 years old. Also, the frame on the Flues is prone to cracking if using heavy loads. You can buy low pressure vintage loads from polywad or RST. They should be measured as well as barrel wall thickness. This gun was designed for the loads back in the day which used different powders than today. Even if the gun is okay to use, do not shoot modern high pressure loads in it. If there is pitting on the inside as well, I would not be firing it. From you pics, it appears there is some severe pitting on the outside of the barrels. I would have this gun checked out ( by a competent smith/person who knows double barrels)before using. If that is a 2 in the first number of your serial number, it was made in 1915.

Ithaca model 100 serial numbers