This is a picture of a Winchester 1873 receiver- 3rd model for your reference while shopping for parts. Note that if you have a 1st model (the dust cover will sit inside two outside rails) 2nd models the dust cover rail was attached to the receiver with two screws (not a milled part of receiver), and the hammer was retained by a screw through the receiver wall (not a pin). 3rd models, the dust cover rail was machined as a part of the receiver (can not be removed) the hammer was attached by a pin through the lower tang and the lower tang screws were moved to the rear of the frame (like in the pic) On models UP TO 90,000 the Loading gate (spring cover) screw went from the outside of the right side plate to the inside (you will see the head of the screw rather than the Forearm of it. Click on the image to enlarge!! Hope this helps
