Unfortunately, the longer a card has been on the market, the more likely the manufacturer is to redesign the PCB. Oftentimes, they do so without changing the model number.

What you seem to have is a redesigned card, so unfortunately the PCB will not be reference and will not work with any full cover blocks.

One course of action is to get a universal block and use heatsinks for the VRMs.

Another is to return the card and purchase a reference designed card. The problem with this is that there's no way of ensuring you get a reference design without first looking at the PCB. You could try asking the retailer if they'll look at the PCB of the cards they carry and let you know if any of them have the words "AMD" stamped near the PCI connectors. (Not all reference design cards will have AMD on it, but the ones that do are definitely reference design.)

I myself have two Gigabyte 7950s (Windforce) that I purchased from a local retailer a few months apart and both are reference design (both fitted with the EK 7950 blocks) though neither have the word AMD stamped on them. Gigabyte has since redesigned the PCB, but I do believe that the redesigned PCB has the word "v2" (or similar) in the model name. If you have a local PC store, see if you can get in and have them open a card to let you check.

Best of luck!