Dux construction kits from 30s

In 30s,  the factory Markes & Co. KG (Lüdenscheid, Germany)  produced metal toys, mainly construction kits (Metallbaukasten) marked Dux. The production begins with kits of planes (very similar to Mecavion) sets: 103, 104, 106, 108, 109, 110 and the complementary sets: 104A, 106A and 106D. These are sets that allow you to mount many types of aircraft (monoplane, biplane, floatplane), but only set 109 was supplied with a motor. The construction pieces were produced in corrugated tin for the wings and smooth to the nacelle. Some pieces were painted red for a pleasing overall effect. The spring motor rotating the propeller and the wheels was  an optional part that could be purchased. In the same time period, the Mercedes SSK construction kit was made  in two versions with and without clockwork motor. As the Mercedes SSK accessory , you could buy the remote driving  flexible cable. 

The Dux 1933 brochure (9 pages) is located here:

http://www.constructiontoys.it/wp-content/uploads/2014/03/DUX-1933-09-brochure.pdf