It reads "Elson's Patent September 15th 1868" and I believe it refers to the following: Patent Number 82097 available from the United States Patent Office (www.uspto.gov) and assigned to Florentine A. Jones (see the attachments below). This patent is not in Tolke and King. I would also suggest that it does not guarantee the watch was itself made in 1868 and it still leaves open the actual date International Watch Company founded.
Greg Steer - January 2002
