[TowerTalk] M2 OR2800P rotor question

[Arliss]

I have a question for the reflector re: my new M2 OR2800P rotor. 
  Due to my work, I won't be able to call M2 for several days, so 
I'm hoping someone here knows the answer.

I recently purchased a new M2 OR2800P rotor and just had the 
chance today to take it out of the box.  Looking the rotor over, 
it seems that I have a problem -- maybe I'm missing something 
obvious, but I don't see how I can use the rotor with my 3" mast.

The drive plate has 4 holes on 3" centers.  Given that and the 
thickness of the walls of the mast clamp, I don't see how a 3" 
mast can be accommodated, although the M2 website states that the 
drive plate accepts masts of up to 3 or 3-1/8" diameter (various 
numbers are listed at different locations).

Can anyone tell me if the layout of the drive plate has changed 
on the current production runs of the OR2800?  Is there more than 
one version of the drive plate in production?

73,  Arliss  W7XU