Seth Thomas offered a remarkable selection of porcelain-enamel dials in different styles and fonts, manufactured by the local firm of Duff & Solace until sometime in 1898, when a fire destroyed their factory at the corner of Center and Litchfield Streets in Thomaston.
It is not known who supplied the dials after that point, but most were imitation-pressed made in Switzerland. None of the later models made after 1900 have been reported with anything but faux-pressed Swiss dials.
An 18-size dial will fit any 18-size movement in both open-face and hunter configurations. They came with only two dial feet at 13 and 45 minutes prior to 1900, when a much-needed third foot was added near the 36-minute-mark.
Single-piece pressed dials were by far the most common after the turn of the century and were used for most of the named grades and all the lower-grade models.
Pressed dials could also be constructed to resemble an imitation double-sunk style (but were still single-piece) and were also found on the all the lower and mid-grade Models 5 through 13 after 1900.
Heavy-font pressed dials were used on the lower-grade models, with numbers 1222 and 1223 having no seconds bit.
Single-sunk dials, or cut seconds dials, are assembled from two pieces of copper soldered together, which are fairly scarce and much thicker than imitation dials. These early single-sunk dials were offered in Arabic and Roman signatures with cursive and block fonts, and they made up the bulk of company's output, leaving the factory on just about every Model 1 through 4 before 1900.
Double-sunk dials were assembled from three pieces of copper soldered together and so are thicker. The rarity of these dials likely had to do with the fire at the Duff & Solace factory in 1898. Including those dials with the scarce Gothic signature, they have been found on only the highest grades of the Models 2, 3, and 5, including Henry Molineux and Maiden Lane.
Fancy dials are also a pressed variant and are a rarity indeed, using gold or silver filigree on top of a colored base. All of the known examples are single-pressed, made in Switzerland, and all have been reported on medium-grade Models 3 and 5.
No Ferguson dials have been reported so far.
The 24-hour dials are believed to be an import requirement for Canadian railways, and they were arranged in a radial style in several combinations of either genuine a double-sunk or a pressed imitation. They have been found almost exclusively on only the middle and higher-grade Model 5s, like the 248, 260, 280, and the Maiden Lane.
The non-24-hour imitation version has been found mostly on the 23-jewel Grade 272, with more than half of the reported examples carrying it.
Henry S. Montgomery designed the railroad Safety Dial layout, recognized by the radial minute markers at the outer chapter and the '6' in the seconds sink. They were available in either a genuine double-sunk layout or faux pressed.
The 24-hour double-sunk dial was used only on the highest-grade Model 5s - the 260, 282, and Maiden Lane - from the final serial number run.
Any painted metal Seth Thomas dial was almost certainly an aftermarket item from the Roaring 1920s, when the Art-Deco style was in full swing. They were evidently designed to replace damaged porcelain originals, and are quite rare. The Model 12/13 Republic appears to be the only named grade that has its own special dial, which was introduced in the final years of pocket watch production. Several raised and patterned styles have been reported.
Most of the named grades came with matching dials (not including private labels), and the company offered replacements for the same cost as the standard dials. The train motif was common and used on the RR Special, Engine Special, and Trainmen's Special.