Beautiful JAS J Duncan & Co. It's been cleaned and sharpened. It's ready to use or added to a collection. The handle is in amazing condition. The medallion is 1" and the split nuts look like they haven't been touched. There is an odd shaped hang hole on the toe.
There was a hardware importer and dealer in Philidelphia called James J. Duncan & Co. in the mid 1800s. It's possible they ordered this custom saw to sell through their business as their aren't any known saw makers with this name.
