Originally in Ithacas the S stamp was the grade stamp for a No. 1 Special. The receivers of a Field Grade (half-pistol grip and Smokeless Powder Steel barrels), a No. 1 Special (Cockerill Steel Barrels and a capped pistol grip) and a No. 1 (Twist barrels and a capped pistol grip) were all the same. By 1919 Ithaca had dropped their composite barrels and streamlined their offerings. The Field Grade got a capped pistol grip, the old No. 1 1/2 with the bold floral engraving and Damascus barrels became the No. 1 with steel barrels and the No. 1 Special and the No. 1 1/2 were gone. Through that transitional period after WW-I you will often find low grade Ithacas with receiver grade stamps that don't exactly match the catalogue offerings.
