But even if the ads are based on David Bedford, I can't see what the basis would be suing the company. I'm not sure that there is much of a legal basis for 'owning' your image. I thought the Princess of Wales' trust had tried to trademark her image and brought cases against unlicensed manufacturers of mugs and so forth. I don't think they had much luck.
And how could David Bedford have suffered any damages - surely he hasn't been financially affected? Maybe he's going to base his case on emotional distress, but that's a bit thin.