Wenco replacement parts for your Wenco windows. Wenco Windows & Doors are manufatured in Mt Vernon, OH. Wenco Windows & Doors Inc produces the following products: Wood, aluminum-clad wood and patio doors with a comprehensive choice of styles and glazing options. Offerings include double hung, casement, single hung, awning and sliding windows; archhead casement windows and custom shaped windows such as half rounds, quarter rounds, ellipses and trapezoids; and sliding, swinging and French patio doors. Wenco replacement window parts are available.