painted bowl

Lovely hand painted bowl 7" dia. X 4" high, finished in hand painted blue and brown brush stripes with a plum coloured bottom and base,
and with what looks like a salt glaze finish around the top , the plum coloured part isnt glazed, there is what looks like ' RCS' on the side which was painted on then the plum colour painted over as you can just make it out when it catches the light ..
Its a great bowl in A1 condition and for 50p at a tip :-) i cant complain..!
Any comments greatfully recieved. ?