I have a bowl and plate done with a partial lusterware finish. The inside of the bowl and the center of the plate are the only iridescent portions of the pieces. The mark on the plate is very clear, the one on the bowl is very faint but in good lighting I can see that it is the same mark. Perhaps there was something under neath the mark as well, or it is a bit of stray ink. Hard to tell. The mark is a cherry blossom, but not the M cherry blossoms I have seen online. Is it perhaps a more modern version? Do you think it is still Noritake, and from the 1920's or 1930's? Or later than that? The iridescence on the bowl is in very good shape, that on the plate is not.