I have a group of pictures from the Illinois State Military Museum that I asked help in posting. The Museum has the "Lincoln Board" that was donated by Spencer's family. There is also a Spencer Rifle # 5801 carried by William Rodgers of Company "C" of the 98th Illinois Mounted Infantry of Wilder's Lightening Brigade. They carried their rifles on horseback until they reached their position, dismounted, and then fought as Infantry of foot, two to three men in line with one man holding the four horses. Number 4 could also be in line if in a really bad situation, after tying up the horses. This rifle has a small ring attached to the left side of the stock, but it is not a carbine sling ring set-up.
(https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/09d427df-5790-4ffd-aef1-dc03636bb089.jpg?width=1920&height=1080&fit=bounds) (https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/09d427df-5790-4ffd-aef1-dc03636bb089.jpg?width=1920&height=1080&fit=bounds)
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(https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/224a8f62-a43a-45ec-93f8-732968bf8abe.jpg?width=1920&height=1080&fit=bounds) (https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/224a8f62-a43a-45ec-93f8-732968bf8abe.jpg?width=1920&height=1080&fit=bounds)
(https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/92da1fc4-2029-4473-8e13-be9c9182d175.jpg?width=1920&height=1080&fit=bounds) (https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/92da1fc4-2029-4473-8e13-be9c9182d175.jpg?width=1920&height=1080&fit=bounds)
(https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/520ec359-7a32-4ef4-a008-fe1c9410f5b8.jpg?width=1920&height=1080&fit=bounds) (https://hosting.photobucket.com/fa3dae8f-92ae-4b5f-a0ad-ae3ab652eb71/520ec359-7a32-4ef4-a008-fe1c9410f5b8.jpg?width=1920&height=1080&fit=bounds)
(Photos posted by Two Flints)
A lot of Wilders rifles have the added "expedient" sling ring. It is made by removing the center bedroll staple from the back of a McClellan saddle and screwing it into the stock wrist. (There are three, so loosing the middle one is no big deal). The ring is often one of the leadstrap rings from down by the rider's knees. There are two on the saddle and you really only need one. The ring on this one looks smaller than a leadstrap ring. I have handled a 123rd Ill Co.A rifle with the same mod. His uses the leadstrap ring.
The McClellan saddle Staple in the photo is brass and screw on type.
These began to be used on the 1885 McClellan saddle,
continued in the 1904 and 1928's.
The CW 1859 McClellan saddle staple were wrought iron and hammered in.
Though I have seen wrought iron saddle staple screw attached on CW saddles.
The Cavalry was still using CW McClellan saddle
in 1870's with modifications (Leather covered) over the 59's Rawhide seat, Rigging and Girth type.
I believe Iron staples were still in use thru 1876 and later.