The part you are refering to is called the Loading Gate,you are correct about last 3 numbers.
Times being what they are makes it kind of hard to price guns as of late,but I would guess $1,500/$3,500,I know thats a big spread but thats why it's called a "guess",check auction sites for equal type gun and you'll get real time going prices,check Cabelas and some of the other dealers and you'll probably find their asking prices to be 15/20% higher than finished auction prices.
RayP.