Mystery Blue Marius Giuge-reminiscent bowls, MD or CW mark

Hi all

I picked up these fabulous bowls recently in a charity shop but can't identify the maker; they're double-glazed, as it were, and the top glaze is really thick and rich. They have a look of Marius Giuge but aren't quite right and anyway the mark is different. They're far too good to be just any old potter and must be by someone who really knows their stuff (I think!) but neither BISPM or Marks Project are showing anything under any possible combination of the letters m, w, C or D, which are all I can think of, bearing in mind I don't even know which way up it should be!

Thanks

Dave