This pulley has been cleaned and conditioned with Fluid Film. This product is an all-around metal, non-toxic preservative. If you were to clean it down to the bare metal it wouldn't look authentic.
The only thing I would suggest is to apply some grease to any parts that move. They are oiled with Fluid Film. If you are planning on using this pulley for a mere wall decoration you wouldn't have to apply any grease. Outside of part numbers in multiple locations and the patent date, there is a upper case "T" in a few different locations.
This may have been the manufacturers mark? This item is in the category "Collectibles\Tools, Hardware & Locks\Tools\Pulleys, Block & Tackle". The seller is "jerryupnorth" and is located in this country: US. This item can be shipped to United States.