The mark on this lamp is for the Tiffany & Co. Store in NY, not from Lewis Comfort Tiffany, which are usually marked Tiffany studios. The base looks like brass. The shades and crystals are almost certainly replacements. (IMO). The numbers usually indicate a model number, the S is likely a makers mark. Tiffany & Co. Items are pretty well documented and I've heard that you might be able to email the store for more info. (I've never tried). Not sure about age, to my eye it's not that old looking, but I'd guess it worth 100 to 200.
