most models of anvils you find are clean anvils, but this is now what they look like when they are in use.a good blacksmith will clean its anvil after use, but during forging, a anvil is often far from clean, especially if the blacksmith is working on a forge weld.
this model is based of a 3d scan of a anvil. for realism, this scan was made while the blacksmith was working. the white paste you can see on the anvil and running down is borax, a white powder that assists in making a forge weld and helps cleaning scale of.
the original scan was very high poly, but by controlled re-topology and baking, this poly count has been brought down significantly without reducing quality. this model is now low poly, ideal for real time rendering and games.