Blue mottle glaze bowl 8" across - mark MB? HB? WB?

Can anyone make any sense of this mark on a jug?

I'm also posting about a bowl with the same mark.

Thanks for looking.

Anyone able to id the mark on this bowl?
My jug posted also shows the second letter more clearly as a B (it could be an R if you only look at this bowl).
Thanks again.

Ive come across the mark before but it’s still a mystery

I pick up my bits and pieces mainly at a local auction house in Pontrilas (Wales/ Hereford borders). It could well be local to here.

Could well be.
Another example -

I’ve merged the two posts because they are by the same Potter

Thank you for merging. I'm getting the hang of it!
Do you think it is MB?

Yes, I think so. I’ll double check the Marks book. Might be a hobby potter but Irish is also a possibility ; their marks aren’t in the book.