I saw these as well on Ebay and was very interested, but as the bids got pretty high I dropped out as I was unsure if they were legit. One of the signs is dated 1970 and the other is dated 1974. Regardless of the origin they are nice looking signs and will look great hanging in a shop.
Here are the 2 links. Seller never says they came from Canonsburg, but they do look like older signs.
Yenko sign 1
Yenko sign 2