Engine Special is a private label trading watch in Seth Thomas 18-size hunting Model 12. 

Engine Special was manufactured as a private label trading watch by Seth Thomas for R. E. Chalmers & Co. of 356 Dearborn Street Chicago Illinois for sale in their mail-order catalog.

There is frequently confusion and consternation among pocket watch enthusiasts, collectors, historians, and watchmakers around the murky identity of “Trading Watches.” In general, the term “Trading Watch” is applied to inexpensive 7-jewel movements that have their pivots covered with “fake jewels”, and have movement markings declaring jewel counts of 17, 19 or 23 jewels. They were manufactured in a different social era that is difficult to relate to in modern times.  Because the specific Trading Watches manufactured by the Seth Thomas Watch Company are all Private Label watches, none of them are signed with the Seth Thomas name.  As with other Seth Thomas Private Label pocket watches, identifying the manufacturer requires knowledge of the shapes and configurations of the top plates of the many models of Seth Thomas pocket watches. Use of the Ehrhardt American (EA) Numbered Drawings permits identification of any pocket watch manufactured in America between 1830 and 1990.