Railway Special

Case and movement by different makers is the normal state

Hamilton sold the movement; the buyer chose the case, frequently from Wadsworth, Keystone or another case company. A 992B in a non-Hamilton case is correct and expected. Treating a case-maker mismatch as evidence of a marriage would condemn most genuine railroad watches in existence.

Railroad dial requirements constrain what a correct dial can look like

Railroad service required bold Arabic numerals, a clearly marked minute track and, on the standard specification, black figures on a white ground. A 992B wearing a fancy, coloured or Roman-numeral dial is either a later replacement or was never railroad-service equipment. Montgomery-style dials with numbered minutes are a legitimate and desirable period variant, and are also the most commonly reproduced.

Serial-number dating on a 992B is approximate by construction

Hamilton assigned blocks of serial numbers to blank plates which were then stored and finished as demand required. A movement can therefore have been completed years after the year its serial number implies. The published serial lists give a production-year estimate, not a manufacture date, and the difference matters when the date is being used to judge whether other components are period-correct.