Inventor of the designer's name was Jaroslav Wanzl, and in 1925 the firm "Mercury", he began to manufacture of iron designer. Production sets continues to this day. The reason that the Soviet industry set about copying the Mercury, and not, say, Meccano, is that the Czech designer was made in accordance with the metric system.
A copy of, unfortunately, turned out to be unsuccessful. When you hold in the hands of the details of Soviet and Czech collections, it comes to mind comparisons Lada and Mercedes. Mercury - colored metal plates with smooth holes, screws that are not thread breaks, wheels with rubber tires. There is even a caterpillar tractor to do.