Frankenstein ZBook 15

Happy Christmas everyone.
For about two years I ran my photography business from a G i7 17" Zbook. It was superb but eventually ceased to be in any understanding of the word a laptop. So, Last year, I sold it and bought myself a custom built desktop editing machine which is far more manageable and upgradable.
Anyways, I've outgrown my ultrabook and bought myself an unmissable Zbook 15". Admittedly, it was second hand and came without memory or a psu as well as only having a 320gb hd. I've installed 16gb and got a spare psu but had numerous problems trying to install a new primary ssd. Bios kept reporting an error with an unidentified mainboard. I eventually got it to windows and downloaded all relevant HP drivers, software and diagnostics. I ran the diagnostics and it transpired that the seller has replaced the mainboard with one from an HP Elitebook 8470 in the original Zbook case.
I can't find anywhere the actual model number / serial of the Zbook case so I've no idea what series the Zbook is. All the USB's seem to work fine. Sounds appears very weak and I can't see any evidence of any Nvidia graphics..
My question is this, if the Elitebook board is i7 2.9 is there any benefit in getting myself a replacement zbook board and if so, how do I determine which series (G?) to get?

 

My question is how on Earth can you fit a 8470 mainboard a Zbook 15? I think you got scammed. I don't think it's worth the hassle determining which mainboard you need.

 

When I confronted the sellers, they said that HP would use parts from other lines in the lower ends of the range however this is using an I7 2.9ghz processor. The laptop seems to be working fine (using it now to type this) and the only suspect issue is that when the laptop runs through bios, it stalls and requires a return key press. It states that it is on step 9 of a production routine/analysis. It certainly doesn't look like a badly butchered machine. My main query when I looked behind the bottom plate was that there seemed to be no visible place for a second drive.

 

Could you provide images of it? It would certainly help.

I'm not really sure how true this is, to be honest.

 

Take the bottom cover off, usually there is motherboard model number somewhere close to the ram slots.
Then you can just search online for the model number or check service manual for your zbook to see if it is correct part or not.

 

G1/G2 boards are interchangeable and the only difference is the Thunderbolt speed afaik.