The far and away most common Ithaca double is the Flues Model, some 223000, which has a bad reputation for frame cracking, and many were made very light and are found with thin barrels.
Flues 16-gauge light weight Ad 1913.jpg
Flues 20-gauge ad, 1910.jpg
I use to think the frame cracking was only in the very light smallbores, but then I picked up a series of letters concerning a 1921 vintage No. 4 10-gauge --
350977 01 Oct 26, 1932, pg 1.jpg 350977 02 Oct 26, 1932, pg 2.jpeg
For 1926, Ithaca Gun Co. introduced the New Ithaca Double (NID) with a stronger frame, new lock work and a rotary bolt, some not fitted as well as they should be. The Field Grade NID was introduced at $37.50 retail.
March 1, 1926 NID Introduction.jpg
March 1, 1926 Price List.jpg
That same year the Godshalks moved the A.H. Fox Gun Co. into a new more efficient factory and dropped the price of a Sterlingworth from $48 to $36.50 a dollar cheaper than a Field Grade NID.
1925 Retail Price List.jpg
1926 Retail Price List.jpg
The price of the Sterlingworth remained $36.50 until June 1932 when Savage upped it to $39.50.