Are you sure you have a 2950 II? According to the order details and this, you have a 'I':

http://store.flagshiptech.com/dell-pr278-0pr278-poweredge-2950-system-mother-board-g1/
http://www.amazon.com/PR278-Dell-Mother-Board-Poweredge/dp/B00686KFNM
http://www.velocitytechsolutions.com/dell-pr278-poweredge-2950-system-board-gen-i-dual-core/

You can tell a 2950 revision/generation by:

• Circled letters II or III on the upper-left corner of the front of the chassis
• Revision field of System/Information page in OMSA
• Order details will show 'II' or 'III' in the chassis description

I don't have the front plate with the sticker on, so I guess your right. I just seen V2 next to the chassis on the service  tag page and assumed it was gen 2. Can I buy a gen 3 motherboard off eBay and just replace it like for like? Really don't wanna be stuck with dual cores. Thanks!

Probably. I've never done this, BUT one thing to check is the sideplane and CD/DVD connectors ... I believe newer machines have different connectors for these devices and I doubt there are "legacy" connectors for them on the newer boards..