Studio Bowl .. Anybody recognise the Studio mark.. i cant make it out ??

Just picked up this bowl... no idea who made it but thought the design very striking and attractive
Have been peering at the impressed mark for ages and cant make it out...
I at first thought it to be a J in an oval but now not sure at all.

It measures about 9" across
Has a light creamy body with a thick brown slip decoration.
It looks like its been spun out to make the pattern but i think its far too regular so must have been hand painted this way.

Thanks for your thoughts.