Mixed clay bowl. Mystery MB mark - Michael Bayley?

Michael Bayley did lots if this type of work using different coloured clays. He used an MB mark, but the one in the book is not like this. I suspect however that it is a different version of his mark which does not appear in the book. Not many potters did this type of work, and he was one of the best at it. It is also a nice, very professional piece. I have had a couple of his pieces.