The Farmers Brace probably has a patent date of 1871 behind the lever. You would be able to see it in mirror image on the back. You are missing the hook. There are some other styles of the Farmers Brace. Paris Styles does not have a patent date on it. Also, it is missing the lever. The presidential one may be around 1892. the one that looks like 2 ovals joined together at the middle is a C.H. GUYOT. There should be 2 of those and one that is bigger and a little different looking. If you search C.H. GUYOT you will probably see a picture of the bigger piece. Those can be pre civil war, but they were made for a long time, so could be later. Sorry, time for dinner! Hope this helps! (Wait- I see the guy posted a picture above. The brass colored one on the left is the bigger C.H. GUYOT.)