Since there is nothing to identify it other than a symbol chances are it is not part of a trademarked logo !! With three identical signs could mean three locations or a sign maker screwed up three times,,or someone ordered a sign and didn`t figure the space correctly and decided this part could go !! Non of which we know !! What I would suggest is to start with the Historical Society in the town you bought them,,go through old town photos and see if there is a match,,ask the older generation that has lived there all their lives !! You might find someone who remembers it !!