Dating in selb
The number usually found under a casserole (Covered Vegetable lid or on a sugar/creamer) is called the Factory number.
Some of the Factory numbers have been identified in the later Schleiger books to a Schleiger Pattern.
Be persistent, and learn what you can from each source.
There is a list of manufacturer’s links on Porcelain Marks & More that may help shorten the search.
Some of these websites have German spellings and the site name ends in as they are German websites, but once you get to the homepage, you can click on the English version.
Backmarks (1) are the mark on the Underside of a plate or item.
There is usually two marks- the Manufacturers mark and the Decorator mark.
Part of the challenge arises from the history of the country.