Even if you would have found something on the markings, I believe that it would only have confused you more. Such items are typical traps for owners and amateurs alike. Please take another look at the saucer.
The impressed word “MEISSEN” and the red marking are of different origin, they represent a manufacturer mark and the mark of a decoration studio. Now, the impressed word has nothing to do with the famous [i]Porzellanmanufaktur Meissen[/i] but is one of the marks used by the [i]Meissener Ofen- und Porzellanfabrik AG vorm. C. Teichert[/i] which was also located in the city of Meissen. It was used in that form between 1909 and 1929.
The red “Alt Konstanz” mark is that of the [i]Porzellanmanufaktur Alt-Konstanz[/i], a small decoration studio in the town of Konstanz, established in 1919 by Mr. [i]Joseph Joehle[/i]; he used shown mark between 1922 and 1927. In this context I should explain that from 1927 onwards, [i]Joehle[/i] introduced new marks, based on his partnership with Mr. [i]August Roloff[/i] from the town of Muenster. [i]Roloff[/i] already quit partnership in 1929, but [i]Joehle[/i] continued business until closing in 1935.
In short:
– Item made by the [i]Meissener Ofen- und Porzellanfabrik AG vorm. C. Teichert[/i].
– (Re)decorated by [i]Porzellanmanufaktur Alt-Konstanz[/i] between 1922 and 1927.