I'm not entirely sure when this happened. The mesh started out fine, but now suddenly I've got some asymmetry that I can't account for, and unfortunately I can't even recall WHEN exactly it happened:
The left arm is correct, the right is not. I tried applying Left to Right mirror, double-checked all of my targets, both stock and custom, and even switched to different Topologies. I'm not sure what I need to do to fix it, and I absolutely don't want to have to completely rebuild the model. If I do create a new model, the symmetry is correct so it's something that has happened along the way. I certainly could fix it in Blender by simply mirroring the left side, but I'm currently having problems syncing between Blender and MH (that's the subject of another thread).
It also shows up in the skeleton, in particular the circled bone:
However I've also tried changing to different rigs and none of THOSE make a difference, either.
I'm using MH 1.2.X.