To make this oiled wood look older, we are going to modify the Diffuse map. It needs more dirt, spots, scratches, etc.
Start with this image:
Add a random image of dirt on a new layer, set it to Multiply, and reduce the opacity.
Add some spots on a new layer, and make this one Multiply as well (most of the time, when adding darker details, you can use Multiply mode).
Now make the whole thing a bit darker using a Curves adjustment layer.
Finally, add a Hue/Sat layer and lower the saturation, using a patchy mask.
Set it up as the Diffuse. Just replace the image at the end of the VrayDirt chain.
This is the result:
In a similar way, add some patches to the Reflect map. The reflections should be darker as well.
Now just make the Glossiness map a bit patchier as well, by increasing the Bump to 3.
