We are trying to replace our gas fire but the marble surround is badly stained by adhesive, varnish, soot and a few other unidentifiable marks! We have tried scrubbing it with just about every cleaning product in the house (including coca-cola and lighter fluid!) and we've tried gently sanding it (and not so gently!) but it's still stained!

Does anyone have any suggestions as to how to get these stains off or how to cover them up??

I'm posting this because hubby's sighing, squeaking & swearing is scaring the woodlice! Plus it'll really annoy him if I go & fix it without a problem!