Hey Trevor,
as you must know by now, FCPX will only take in properly op1A mxf,
as opposed to op-atom mxf which is the format used by the avid.
Your question got me interested so I did a quick search
as it seems you'll really want some 3rd party app
to do a conversion between the two formats
and found this:
http://www.mog-technologies.com/solutions/developments-tools/mxftools/
Seems the mxf component suite has tools for rewrapping op-atom mxf into op1a,
and maybe also for advanced metadata handling.
The price is not mentioned though,
so you'll have to write them to get more info.
Hope it helps,
keep us posted on your findings!