I have not been able to find where these shotguns originated, but the reason I am replying is due to the fact that my finch arms 12ga. single barrel is also stamped with 200743
No
With the serial number that you provided,your Ithaca double barrel shotgun with the damascus barrels was produced in the year 1900.
Check the barrel and receiver
You may have to break the shotgun down in to the barrel section and the receiver section first.Look under the barrel section on the flat just ahead of the lug for the serial number.
look on the breach, barrel.
1896
Check the receiver and barrel
Try the receiver, barrel, forend
Who made it, what caliber is it, is it a rifle, shotgun or hadgun, how long is the barrel, is the barrel round or octagon, what is the stock made out of, what is the serial number(if any)? Who made it, what caliber is it, is it a rifle, shotgun or hadgun, how long is the barrel, is the barrel round or octagon, what is the stock made out of, what is the serial number(if any)?
Check the frame and barrel
next to the barrel
Try loooking on the reciever, tang and barrel