The board is legit, it IS for bitfury chips and I know the 55nm chips will have a similar packaging.
I am also a bit wondering how you can know that 11mmx11mm chips are similar than 7mmx7mm chips?
Not sure if this is the answer you are looking for, but the packaging is similar (QFN) just larger and the Engineering team has worked extensively with Bitfury Chips so I'm fairly confident that this will be similar.
Elaborate on your definition of similar and I'll try to answer better.