Here are four less common markings from four different countries! $8 each or take all four for $25 plus actual postage

U-1225 Germany - dome inkstamped RIG (Rosenthal Isolatoren GmbH) - VNM

U-1228 Serbia -- Marked with the logo for Elektroporcelan Arandjelovac -- VNM

U-1246 Switzerland -- dome inkstampped the Swiss Langenthal logo - cool piece -- VNM

U-1692 China -- skirt embossed as you see -- VNM