can someone identify the manuf. of a pilot orifice?

I was working on a gas 40 gallon American water heater today. Has a Robert Shaw gas valve. The pilot orifice is somewhat plugged. The pilot orifice has 1 N 1 stamped on it. Does anyone know who the manufacturer of this orifice is and where I can buy a kit of these orifice inserts with different sizes. My local plumbing supply doesn't sell this waterheater's bracket assembly and I'd like to get an assortment of orifices because when they are that small you can't clean them.