My serial# listings in Rogliatti and in the Hove Collectors Books Leica Pocket Manual list this serial# as a Standard from 1936. The fixed in place viewfinder, and only one accessory shoe, distinguishes it from the 1c which has two accessory shoes. The slow speed dial is not so much deleted as not added. Many Leicas have a blank cover where the slow-speed dial can be installed during a factory upgrade. An interesting detail is that the slow speed dial cover illustrated for the Standard in Rogliatti is of plain metal, where yours is decorated with a vulcanite circle. Lager's illustration shows a standard with no slow-speed dial cover at all. The Hove Pocket Guide is the same way.