We have a large antique French polished side board which has developed a smudge on the front drawer. It is very obvious, because the rest of the piece is beautifully shined. I am not sure how I should get it out. I don't know what it has been caused by, but rubbing it with a soft cloth does nothing. I don't do anything to the piece of furniture except dusting with a dry microfibre cloth, so it is not furniture cleaner. Can anyone give me some suggestions?