Novice Q - bit rates on HPX500/900

So I'm doing an edit in the next week, matching some HPX500/900 footage. I was delivered an HDD loaded with files from these two cameras. The footage from the 900 was pushed through a nanoflash during production, and from that cam I've got loads of MOVs. The clips from the 500 are still in their original MXF wrappers. No problems there, I did some test loads of these clips into final cut, they play fine, etc.

My question is, the footage in FCP is listed at 12/14 mbps respectively, and I was expecting all the clips to be at 100 mbps. So, either the DPs messed up on set with their file settings, or, more likely, the 100 mbps footage is in the clips, but FCP just downconverts when it imports? So how do I get at the footage in its full quality?

One thing that worries me is - the total size of the files I was delivered is 65GB. At 100mbps, that would only be, what, 10 minutes of footage? Instead, I've got more like 70 minutes of footage - and at 100mbps, I should have something like 400GB right? Maybe I can get the MXFs in 100 mb/s but I'm screwed on the MOVs?

Anyway, I really appreciate any help anyone can shine on this. Thanks in advance.