Hi Mark,
Thank you for this info regarding your success wit B707 and CIVA.
It sweetens the pot (no pun intended ~;)
 I had IMO acceptable success with B727 and CIVA tonight using some
considerably unorthodox preparation and startup procedures.  A fun
(INS) fright from Guam (PGUM) to Kwajalein (PKWA). I have prepared
a somewhat detailed checklist,  and if I'm able to duplicate success
on two more frights I will submit it in 727 forum for use by those
eager to "take the plunge".  CDU Battery caution light stayed out,
Auto Pilot worked, with exception of an annoying but manageable
issue with the pitch channel.  INS connected with the Heading
Channel of the AP, and the aircraft followed the flight plan.  Even
was able to load two *.awc files via the trusty dusty ADEU.  
Best regards,
Ken

UPDATE:  I've had enough success with CS B727 and CIVA to
allow uploading my startup procedure.  If interested,  you can
find it in the "B727 Captain" General forum.