This Springfield Armory manufactured receiver assembly is for the model 1868 trapdoor rifle and is in very good condition exhibiting a grayish brown patina with faint traces of original oil quenched blue finish and a few spots of rust and pin prick pitting. The receiver assembly consists of the receiver, ejector stud and the breech screw (aka tang).  (file photo)

Note: the following serial numbers have been observed on this model trapdoor rifle: 2450, 3180, 14263, 18822, 29600 & 46073