Pictures of my rear differential

[Diesel Fumes]

Can someone confirm this is a stock diff?

This came with the car. Im looking to swap it out with the Nismo diff it has. Does the diff look terribly bad? It seems fine to me, but again I don't know what to be looking for if there is a problem.

 

[Shaun]

Yes thats a stock item

 

[Keira]

it also looks like its been brought up from the sea bed :lol:

 

[Diesel Fumes]

Can I install this diff or is that not a wise idea? If I do install, how should I go about cleaning it?