If a 20 gauge Ithaca side by side shotgun serial 220098 has an 'S' over '20' stamped on top of the receiver where the barrel rests is this a Sousa Model?
From your description this appears to be a Flues model produced in 1912. Sousa guns appear to have had a lot of fancy engraving on them. The "S" on the metal on your gun does not stand for Sousa. Judging from gunbroker.com auction prices, your gun is probably worth $350 - $550, depending on condition and how badly a collector might want one.
On my 1950s vintage Ithaca Model 37 16 gauge it is on the right side of the end of the receiver where the magazine tube and barrel go into the receiver, and also on the barrel adjacent to the number on the receiver. The numbers should be the same on both the barrel and receiver unless the barrel is not the original barrel, at least on mine they are.
look on the Side of the recevier there should be a Serial Number on the older Ithaca Model 37 the serial Number was stamped on the receiver by the magazine tune and Barrel . also if you take the barrel off on the bottom of the barrel you'll find the matching serial Number. then look up WWW.SURPLUSRIFLEFORUM.COM in their search engine type in ITHACA 37 DOM match your shotguns Serial number up with their chart…
What is the value of a ithaca 1904 lewis boxlock double barrel grade 5 engraved 12 gauge shotgun stamped?
What is an Ithaca double barrel shotgun with Smokeless Powder stamped on the barrels worth Serial number 284123?
You haxe a Ithaca model Flues double barrel shotgun which was made in the year 1917,by the serial number you have provided.As to value that cannot be determined without a more detailed description of the shotgun in question,to include gauge,barrel length,double trigger or single.It would also help if you describe the overall condition of this shotgun to include the amount of blueing remaining and the condition of the wood.