I actually did this for a class of mine about a year ago and it just sat on my laptop collecting dust when I came across it today and decided to upload it. The barrel on the left has a bump map and a specular map on it in addition to the texture. The barrel on the right is what it looks like with just the texture. Each barrel is ten polygons. I guess that's it.
bump map is VERY intense. tone it down abit and put a mask over the rust, the specular would not be the same as it appear on the barrel. good work though