I have found that you can revive tufnol by rubbing/painting on a bit of linseed oil. Dont know how it works but it darkens it and makes it look less sad.
I've bought a couple of tufnol winches on eBay which were very dull and dry. I oiled them, like Abigail above, amazing difference. They really soak up the oil so I guess tufnol must be porous.