OK that was weird, BSG Wiki on my mobile had the Valkyrie listed as the same type seen in Hero and included the stuff with B&C and the photo of the ghost fleet showing the Valkyrie (it's there on the latest video, wide shot as they first find the fleet, at roughly 8'51" in, centre left of frame, or in the wider shot preceding that there are two Valkyrie-class ships in view).
Then I jump on the same site on my laptop and it's the original article. So I go back to my phone and it's the original article there too!
So it may be the Galactica-class Battlestar after all. I sincerely hope it is, for two reasons:
- If it's the same ship then - as The Wormhole
said above - Adama would have seen two of the ships he would later command.
- It would take the tension off what potentially may happen later in the story; if the ghost fleet were to have a battle at the end of B&C then it's a sure bet at least the Valkyrie survives.