Not B6 parts.
B6 arms begin with 8E0.
Hmm, seem different to mine.
So the B7 ones have different attachment points, unless they're the same, and I can't remember.
I bought both the arms and blades at the same time, and they were a doddle to mate together.
have some adapter cones if you want....
£5 and I will post them to you for free