Featured Fine Quality Imari-Style Plate - Origin ???

I'd be grateful if anyone were able to shed any light as to the origin of this Imari-style charger. It measures c. 31cm diameter and appears to be of high quality.

Because of the blind stamped numerals, I assume that it is probably European and probably 19th century. Mason's Ironstone is perhaps a possibility, although I haven't yet managed to find anything similar to it.

Any help gratefully appreciated !

 

Pretty plate! Is that an incised S or something under the center cord in your photo? Can't quite tell if it's just a shadow or something real.

 

Frayed string I think

 

I don't know what others think, but I'm seeing a slight "flow" to the cobalt blue as in "flow blue" china. Flow blue is from 1820 on up through the Victorian era. Nicely done plate, but my guess would be later in the 19th c. Don't think Mason's, but no idea on maker.