Ok, update. I figured out how to remove the glove box. It is more involved than the other models of Lexus apparently. If you want to know, just ask.
BUT...now that everything is out of the way, I would like to clarify my questions in light of recent observations:
1. I took off in the car earlier and for whatever reason the heat came on and worked just fine.
2. I pulled back into my driveway and put it in park, then the heat changed over to cold air.
3. Took off again and the heat never came back on.
4. Looking in there where the glove box was, there is only one servo that I can easily see. It is in the up position which implies that it should be channeling heat. However I am basing this on the pictures I saw of a Lexus 300 that someone had posted.
5. I tried undoing that servo and manually moving the arm part that the servo acts on, moving it up and down...no difference to making any heat come out.
6. Anyone got any thoughts?