First had top alarm shutoff knob, later had back shutoff. The price change book (see references) has the first price data given as July 17, 1933. It says "Discontinued Jan 1936 – Plain #10)" but the Tick Talk shows it as a current model in July 1937.
The price change book says "New Model" by the Jan 6, 1936 line - was that when the alarm shutoff was changed?
Examples of the Westclox Fortune Black Plain Alarm Clock:
Movement Date: 3 36. Does not say "Fortune" on the dial. Movement Date Location: Outside Front Plate on Both Sides of Alarm Escape Wheel; Movement Material: Brass Movement Plates.
Documents Showing the Westclox Fortune Black Plain Alarm Clock:
Document Date: 1935 Document Title: 1935 Westclox Catalog -> 4 Photo Match: Black and White Photo Model Description: FORTUNE. Nothing in its price field combines the quality and beauty of this dependable Westclox. It's an alarm clock, truly a fine example of modern design. Fortune;s square case stands on a substantial base . . . finished in black with nickel trim . . . a beautiful combination that appeals instantly. 25 hour movement with clear toned inner bell; convenient alarm shut off. Fortune is 4 1/2 inches high, has a convex glass, modern hands, decorative dial with clean, bold numerals that make a very attractive and legible combination. retails $1.45. Model No. 10. Westclox Sales Number: 10 Retail: $1.45 USD