Tiny porringer with Leachish decoration, SJ mark?

Any idea who made it?
Thank you for any help with identification.

Looks like an SSJ, SJ or JS mark, with an X and ‘75 date
Not one I recognise

Very broadly speaking. Generally, studio pottery that only has a written or incised  signature on tends to be by a either a talented amatuer or a professional potter who did not practice for a long time. The 75 would indicate made in the 1970's.
This was at the height of the boom in individual people learning pottery making. It was a very popular alternative life style amongst the Post war Baby Boomer generation.
        Unfortunately, it was a poorly paid job. Many excellent potters stopped working. This is an excellent professional piece. But probably unidentifiable.

Looks well potted. Possibly an early piece by JS Stuart.
https://www.20thcenturyforum.com/t22763-ajs-or-js-stuart-quayside-pottery-exeter-painted-jss-mark

I didn’t see the number 75. To me it looked like an wonky ‘p’ with some dots around. Well done! Looking with your mind not just with your eyes.
I don’t mind if I don’t know the potter, it’s interesting to know the context into which the pot was made.
Thank you both for your help!

the decoration reminds me of Simon Rich's early work, after leaving Aldermaston Pottery. And the pot itself looks similar to Vellow Pottery. Maybe by someone who trained there.