Bearing Stamp Code problem

[Nissan200sx_RS13]

So I ordered from nissan new rod bearings(CA18DET). The stock ones are grade 0, but I need grade 2. The difference in part numbers is the stock ones(the ones I removed) are 12111-D4200 with grade 0, but the ones I ordered are grade 2 with part number 12111-D4202.
Here is the problem:

I just got the new bearing(right. On the left is the old, stock one) which is supposed to be grade 2. The box states its part number is 12111-D4202 but the bearing's stamp is 12111-D4200 as you can see at the pics. I ordered the grade 2 from Nissan, is it possible that they sent me wrong bearings?

And another question, the box states that there sould be 8 bearings but nissan told there are out of stock and they ordered them seperately. So they arrive at different dates and different boxes. Is that ok?

http://i867.photobucket.com/albums/ab233/Nicks13/Picture%20176.jpg (http://s867.photobucket.com/user/Nicks13/media/Picture%20176.jpg.html)

http://i867.photobucket.com/albums/ab233/Nicks13/Picture%20177.jpg (http://s867.photobucket.com/user/Nicks13/media/Picture%20177.jpg.html)


And last
As I was searching on the net I found this on nicoclub

And I just had an idea.

I've noticed that regardless of the grade of the bearing (I have all 3 sizes in front of me). The stamped part number is the same; 12111-D4200. Then depending on the actual thickness, they're color coded. Grade 0 is no color, Grade 1 is Brown, Grade 2 is Green. The way they're color coded is as simple as a colored sharpie/metal stain on the thin side of the bearing.

Any idea if this is true?