I decided to email the site Pottery Marks and More and here is the wonderful reply I got!anice,
"Another example why pictures say more than a thousand words - not Oscar Schaller. And I nearly missed it in my archive as the one you have is listed under 'R', has a minor addition and is flagged 'mostly printed'.
Per description I would have missed it as it's not one of those I have memorized ... anyway, would be great if you could send me the original unclipped or newly taken shot of that mark as I don't have exactly *your* version and I'm always looking for clear pics to add to my archive/website.
But back to the plot: the mark in it's printed form has a banner over it reading 'SCHUTZMARKE' (registered trademark) and two additional laurel twigs horizontally pointing left and right from the middle underneath the anchor. My scanner kicked the bucket so I can't scan at the moment but I guess you get the picture (LOL!).
Now, the top of your anchor looks funny - that is the letter 'R' with it's left 'leg' connecting to the vertical anchor bar. Then we have the 'Z' on the shaft, then 'S' on the left side plus finally a funny 'C'-squiggle on the right - that's 'Co'

Gives us "R. Z. S. Co." and that's easy: ta-da! company was "Zeh, Scherzer & Co." from the town of Rehau in Bavaria. Marking registered (together with another one) at the "Koenigliches Amtsgericht Rehau" (Royal District Court in Rehau) on August 3rd 1882; the mark itself was used until 1896. The successor mark is another one of those where I only have a vague sketch and description so far, so I need to get pronto and update the site

Location and manufacturer found, mark dated and happy. Only thing I can't help with is a value or sorts as I am absolutely no good at that. Marks and history is my cup of tea but everything else ... beep! brain timeout!
LOL! Hope that helps,
Chris"