Help! Unusual Square Landscape Vase Signed FS? SF?

Hi, would love to know if anyone can identify the potter of this unusual square form vase with what looks like, to me,

an incised landscape (hills) design and only partial glazing.
The base has both painted and incised letters 'SF' or 'FS' depending on which way you turn the vase!

Interesting piece. The letters SF bring to mind Sheila Fournier who did a lot of interesting work when working with her husband Robert at Lacock Pottery. This reminds me of using the texture of the vase to explore the image wanted. You see a landscape. It could be a beach and waves,
or desert and dunes. Its very simplicity encourages the imagination. Could not definitely say its her work, just reminds me of the sort of thing she might have done. Robert Fournier also used texture to explore the nature of the item, in his pebble vases.

Reminds me of Peter Hayes’ work