Harley, Alexander, Watchmaker & Jeweller, 41 High Street, Dunfermline, Fife. 1877.
Harley, David. Watchmaker (probably a journeyman), Inverness. 1871, Living in lodgings. Son of Alexander Harley, shoemaker, and Jean & Jean Hutchinson. A watchmaker and jeweller at 17 High Street Dunfermline, Fife, in 1874, at No42 by 1888, at No 22 in1914. In 1881 aged 34, a widower, living with his parents, employing three apprentices. Admitted as a burgess of Dumfermline on 6 Mar 1890. By 1891 living with his second wife Catherine, and children Alexander (Born in 1879 by his first wife) and James.
From "clockmaker & Watchmakers of Scotland" by Donald Whyte.
Your watch was sold in Dunfermline, then someone took it to America, so your story starts there with the American fob and chain.
Good Luck.
Allan.