Chrono-mentor, No. 350
15-jewel 16-size damascened nickel adjusted movement with separate shaped train and barrel bridges, jewels in settings, stem wound, lever set (lacking crown), straight line lever escapement, bimetallic balance, overcoiled spring, micrometer regulator, gold cuvette, damaged white enamel dial with roman chapters, subsidiary seconds at III o'clock, date ring at IX o'clock, blued hands, associated Sheibler case with reeded bezels, accompanied by a spare dial signed "O'Hara Dial Co., Waltham, Mass."
51mm, 106.7 grams