can you go into close-up mode Helga, and provide a picture showing the join where the 'decoration' meets the outside of the bowl. If hot worked i.e. applied separately, then it should be noticable that these columns/supports are not exactly at one with the bowl (almost an inset crack where the two parts meet). If the whole thing is pressed in one go, then it is probable there will be very small radiused curve where the decoration meets the bowl. Seams can, apparently, be removed by skillful workers, as Lustrousstone has told me before. Sorry, but I haven't the remotest clue as to provenance.
