I am having quite a strange problem with the way my model renders. After modeling one of the objects of my scene, I created a quick light/camera setup to check the result of some hard surface modelling. When I set the 3D window to Render View, I get the object with what appears to be a scratches texture

the problem is that the object doesn't have any material applied; I have literally only done the modeling; when I apply some material to the surfaces, the material gets applied but underneath I can clearly see the "scratches".

I have tried to append the geometry into a brand new file, and the problem appears to be bound to the geometry itself; the geometry is not perfect (it is mostly quads) but I don't think the problem is related to topology, for it happens with any object in the scene (including a satellite dish model with perfect topology). An interesting clue is that the actual render appears to be totally clean of any artifact.
I know this problem is not a deal breaker (specially since it doesn't seem to show in the final render), but I really would like to know what the solution to this quaint problem is.
Blend file available on request.
Can anybody help?
Thanks in advance.
Sept