Large stoneware studio bowl for ID

A pleasant enough piece, a little like Andrew Hague's work, but much more understated.
Not perfectly potted, somewhat wonky in more ways than one, though I don't think it is by a hobby potter, but happy to be corrected if I'm wrong.
The impressed mark is not one I recognise and having wasted two hours trawling through the bible, I thought I'd try it on here.
Possibly a CY and another letter.
Any help with ID welcomed.