Clemens-Auguststraße 18, Wesselstraße 9, Bonn am Rhein. North Rhine-Westphalia.
Künstler Malerei / Artist Painter
Founded in 1829. In 1870 they were trading from Clemens-Auguststraße 18. By 1902 the company was owned by Jac. Reuther and was based in Wesselstraße 9. A porcelain decorator by the name of Emanuel Mendel was listed in 1932 as working for Wessels's Niederlage in Wesselstrase 9, Bonn am Rhein. They changed their product range to sanitary ware 1929 - 1950. However they also started a distribution arm called Wessel's Porzellanmanufaktur und Engroslager Boehringer u. Co. K.G. which also operated post-war in Ludwigshafen am Rhein. Rhineland-Palatinate. They also had their own wholesaler at Wessel'sche Porzellan Manufactur.
The factory finally closed down in 1969.
Reference: Porcelain Marks & More Bonn Adressbuch 1902 Other Addressbooks
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One litre transfer decorated stein, made for export. 
Basemark on the featured stein above. This mark was for export designated production. 
Ink stamped mark dated 1875 - 1900. 
Post war plate, manufactured by Johann Seltmann of Vohenstrauss
Stein commemorating the 16th Deutsches Bundesschiessen Hamburg 1909.
"Wessel, Hamburg" The author can find no Wessel / Wessell in the Hamburg address books for 1909, so is confused as to the Hamburg mark. 
Wessel's Porzellanmanufaktur Boehringer & Co. K.G. mark from a Marzi & Remy stein with the painted design "Guards Division (Rhein)" dated after August 1945, until 1970. 
Another Boehringer mark. × 
Corps Palatia, Bonn. "Palatia sei's Panier" "Fortis ut Palma Florebit". 1/2 litre stein.Date of establishment of this association: 10/08/1838 
Ludwig Wessel signature, together with impressed Wessel mark on student stein above. 
Base marks on a water pitcher. Dates assumed to be 1875 - 1900. 
Ink stamped mark dated 1875 - 1900, on coffee cup & saucer set. 