Westclox 61-F Dura Case Windup, 2 key, alarm clock Date 1930 - 1934 Nickel plated heavy metal case Dial Metal Patented U.S.A. No. 1709146, No. 1358457, No. 1563431 Patents Pdg. Model No. 61-F 61F. One of six "Dura Cased" clocks introduced in the early 1930's. Part of the LaSalle Series. The clock has a very heavy metal case. All six are highly collected by Westclox enthusiasts as well as other clock collectors. Most try to get the entire set of six to complete their collection. This clock is dated May, 1930. I have found this clock with 2 slightly different dials. The first is silver while the 2nd is gold. Notice that "Westclox" is printed differently. Second clock is dated April, 1930. The "F" with the dot is sometimes misread as an "E". There is no model 61-E 61E.