"The Dueber Watch Co." 21 Jewel, 18 Size ON3L-A. Double Sunk, "Canton" Dial. 

Gold Filled B&B 'Royal' Screw Back & Bezel, Open Face, Plain Back Case. 

The Original had a "Canton" marked Dial as well but it had Chips & Cracks, so I found this replacement.

The Dials that had "Canton, Ohio" below the "Hampden Watch Co." script are found on the 21 Jewel, 18 size, Adjusted & Adjusted to 5 Positions,  John Hancock, M3 & M4's.  Also some of the "The Dueber Watch Co." 21 Jewel, 18 size, Adjusted, Open Face, models had "Canton" Dials as well (as this one originally did) . I have seen some 21J Special Railways w/ this Dial as well, {both Adj. & Adj. to 5 Positions Models}.