I have a Hampden 18S, Model 3, Grade 56, 15 jewel, lever set pocket watch that was made in 1887. I have not been able to find much information on this watch other than the year it was made (going by the serial number). I got it cheaply enough online two years ago, and just got it back from the repair shop a couple days ago with a complete overhaul/cleaning and a new mainspring (the old one had broken). The movement appears to be fully gilded, and says "adjusted". Has a micro-adjustable regulator. The only similar watches I have seen are the Model 3 Grade 60 and the Model 2 Railway (same as the Model 3 Grade 60 but hunter cased), and neither of those seem to have the patent regulator, from the photos I found online. I have heard that the 15 jewel 18S Hampdens marked "adjusted" were considered to be "railroad grade" for their era, but have not been able to verify this.