Glenn,
I got it fixed just in time to fly home. I am just happy it was fixed. It was a broken wire behind the instrument panel. Cost was a lot...troubleshooting and buying HSIs and a new DG (returned that puppy for a $300 restock fee). Overall, it could have been worse: for 4 days the avionics specialist could not locate the problem. It was only when he found that the DG was not getting 28V that he traced the wire to the instrument panel and found the break (after having to pull the instruments and drop the panel). That was Friday afternoon... LOTS of spaghetti wiring in this 1964 aircraft.
However, that said, she flew flawlessly on the test flight on Saturday and on the flight home Monday morning, so I am happy. I'll try Sun n Fun again next year. Just was not meant to be this year.
I got some nice IFR time on the trip back... ;-)