Rust Red, Greens Studio Pottery Jug Illegible Mark - Help identify please

This is a quality jug with interesting glazing and colours. I know it is probably a coincidence but about 12 years ago, I bought this together with some Robin Welch goblets and thought there was some similarity with the colouring. The mark looks like a rectangle inside which there is a large curl like a c. Any help with identification much appreciated. I have been puzzling about the maker of this jug forever. kind regards and thanks for looking

I think it's Eric Stockl's S mark

https://www.20thcenturyforum.com/t9718-eric-and-meira-stockl

Many thanks for identification. I can see the resemblance to that mark. best wishes