Studio pottery mugs, all slightly different. Who made these please?

I bought this set of 6 mugs at a local charity shop. They are hand made, slightly different sizes etc and only one has a mark. I don't recognise the mark, any help is appreciated.

Interesting set. Not a mark I’ve come across before. They look ‘70s

They came from the same charity shop that sold me the set of Tregaron pottery kitchen containers which I posted on here. Maybe originated from a similar area? There is no certainty that they are British made( but they do have a sort of UK look about them). We'll see what happens, usually someone will have seen this kind of thing before and come up with a name.