Caithness was more of a subconscious thought. It may well be a red herring in this case as I had a fairly extensive look a few days back and couldn't find a match.
I had a look for the other bowl earlier today, which was the same as the earlier two in this thread, unfortunately it had been sold, so unable to add a photo.
I've seen a few around over the last few months, so will keep my eyes peeled.