any ideas

Love this but can't work out the mark I think its the line swirl in the first photo

I quite like the patterns made by impressed doilies, but I suspect that 'potter's mark' is perhaps just a loose thread from the doily that was used. There are several areas on that doily impression that indicate the doily wasn't in perfect condition (I think being used to impress clay would be a hard life for a delicate doily!)

This looks like the work of a lady from around Hamilton way ..... I can never remember her name, but I don't think I ever saw a mark on her doily work, which she produced in great quantities.