Hello Wojtek and a great welcome to you. Poland possessed a large number of very attractve sidewheel paddle steamers on its rivers and estuaries. At the outbreak of World War 2 most had been converted into river gunboats and hospital ships and served well. One was unique in that it had a twin rotating torpedo tube on its deck !. Maly Modelarz once produced a card kit at 100th scale of a sidewheel passenger steamer but its name escapes me! (Old age!!). In the 1930s Poland also built a Flotilla of small sternwheel armoured minesweepers designed for narrow channels. They were very utilitarean, powered by diesels but would make a very simple unusual model. Regards, Walter.