Around this time I know Old Overholt (rye) had a barrel proof in the market (or had had one), one member on the other board owns an example I know but I can't recall who it is. The proof is probably around 109, 110.
For this product on the right of the photo, the label doesn't seem to say. Clearly by this time Charles Farnsley was Mayor of Louisville and the products before him were not (from what I can see) just representative of Stitzel-Weller, i.e., I presume he was vaunting a selection of local produce as a Mayor should. (I assume too he was the Farnsley associated with S-W or related to them at any rate).
The Copperhead seems to state (it is hard to read) it is bottled by W.I. Wathen and possibly for some type of charitable group but the legend which might explain that is hard to read (at top of label). Rebel Yell was bottled for himself which makes sense due to the Farnsley connection to S-W.
The proof of the Copperhead would probably be in the range of what we see today for barrel proof whiskey.
I am sure all those bourbons were very good!
Gary