Since the subject of dates for Montgomery and other marginal or continuous minute dials came up in another thread, I thought it might be informative to use period info to establish when these dials were generally available. Since the info is handy I'll start the thread with Rockford (pics are of originals in my collection). 1907 Rockford material catalog shows no such dials. 1911 12s material catalog shows Montgomery dials available for 16s and 18s. Jan. 1913 catalog shows Montgomery dials avaliable for 16s.