CS L1011 Navigation System

OK, the CS L1011 has been out now for a couple of months for the Prepar3d Version and longer for FSX.  The problem is navigation other than VOR.  I have been trying to refit either a GPS or the ISG FMS to the panel of at least create a separate screen panel for them.  So far, no luck and does not look like anyone else so far has been able to.  When I try to add the panels, the panel once loaded will not show any digital readings.  The INS on the current model is not exactly stellar to say the least, so if anyone thinks they can crack this nut please let me know.  It is a great flying aircraft and looks great on P3D but sucks because it is NAV Challenged!