Antique Key-Wind 'Warranted Railway Timekeeper' Pocket Watch

This is an antique, oversized open-face pocket watch, likely dating from the mid-to-late 19th century (circa 1860-1890). The watch features a white enamel dial with bold black Roman numerals and an outer minute track. Below the 12 o'clock position, the dial is marked 'WARRANTED RAILWAY TIMEKEEPER' in an arched serif font. It includes a subsidiary seconds dial at the 6 o'clock position with Arabic ten-second markers and a railroad-style chapter ring. The hands appear to be steel; the hour and minute hands are simple thin spades, while the sub-seconds hand is a slender needle. The case is constructed from a heavy white metal, possibly coin silver or nickel silver (German silver), showing a significant dark grey patina and localized tarnishing. It features a hinged case back and a large circular bow at the top attached to a ball pendant. Attached to the bow by a primitive twine string is a separate watch key, indicating this is a key-wind, key-set movement rather than a stem-wind. The crystal shows minor surface scuffing but remains intact. The overall condition reflects heavy utilitarian use, consistent with an authentic 'railway' style timepiece designed for durability rather than luxury. There is no visible branding for a specific manufacturer on the dial, which was common for private-label or Swiss-export pieces intended for the British or American markets.