Really ?? There is never a man around when you need one is there ?? Thought sure Friedrich would have been here by now !! But at least you know what they are !!
http://www.porcelainmarksandmore.com/site/search/index.php?zoom_query=Volkstedt&zoom_page=1&zoom_per_page=10&zoom_and=0&zoom_sort=0
There are two pages of Volkstedt info and when you click on one you will find the marks at the bottom of the page !! In case you need more info !! Many of the German mfrs have long histories !! This is the best site for porcelains of that region !!