Hello man!
I found some issues with axis rotation. Model id exported/imported with incorrec rotation.
If i change this in your scrip i got ok in 3dcoat.py:
LINE 237: bpy.ops.export_scene.obj(filepath=coa.applink_name,use_selection=True,
use_mesh_modifiers=False,use_blen_objects=True, use_materials = True,
keep_vertex_order = True,axis_forward='-Z',axis_up='Y')
LINE 371: bpy.ops.import_scene.obj(filepath=path_object,axis_forward='-Z',axis_up='Y',use_image_search=False)
LINE 482: bpy.ops.import_scene.obj(filepath=new_applink_name,axis_forward='-Z',axis_up='Y')