G3 to G8 script possible?

So the Autofit for G3f to G8f always fails under the arms for me...the mesh stretches to pieces, so I fall back to Sickleyields conversion 

Is setting the preferred base, and transferring rigging to shape possible via the SDK?  If so, if you can point me to the right spots in the doco, I may write up a script to save some time.