OK... Now that that is out of my system...
The audition went... I'm not sure if it went well, went just-OK, or went otherwise, but it went, and I walked out of the room not feeling like I had totally embarassed myself or wasted anybody's time.
I had fun. And that was the point of the whole adventure.
I do have to say that it was the first time I was nervous enough to actually feel and acknowledge that I was nervous. And, of course, none of the nerves really hit until it came time for me to sing. The sight-reading part went fine - and, actually, since I had not been sent the piano music ahead of time, I got points for sight-reading the piano material.
The singing went OK. -Boy, am I used to the higher keys! But it was passable, if just a bit nerve-inflected.
Breathe, Jojo, breathe! And the reading was OK too.
It was great seeing the casting director again, as well as the music supervisor.
And now... I believe I'm in the mood for a cocktail!