http://www.gunbroker.com/Auction/Vie...Item=463653535

I was bidding against you, but being retired I have better uses of the money.
I am not sure you even know what you bought:

There is a small run of Ithaca RIOT guns, probably less than 500. The numbers do NOT appear in the Ithaca archives retrieved from the National Archives.
They are UNIQUE. They are marked EXACTLY as shown in the auction, and are the only Ithacas so marked - with the US and NOT RLB.

It is though by collectors that these guns were bought from some distributors stock, NOT direct from Ithaca, and an arsenal someplace (NOT Springfield Armory) cut the barrels down and marked them with the hand stamped US.

All the guns that have been seen so marked fall within a narrow serial range of about 500 numbers, so the actual number is likely far lower, maybe as few as hundred or less. This is the first one I have ever seen on the loose.

Of course, the next project is to find some wood for it to restore it.

Congrats on a great purchase.