Well, today I started the investigation....
The very top piece is held on by 2 plastic pieces...
IT IS NOT MEANT TO COME OFF, AND TAKING IT OFF WILL BREAK THE PIECES
*THE NEXT PICTURE IS THE PIECE YOU ACTUALLY WANT TO REMOVE*
So the diagram from the book is wrong, what you actually want to take off via 2 plastic clips and the metal piece is the 2nd part down... stupid 370 book. This piece was easy to take out with a flat head screwdriver putting it in the crease between the plastic piece and the dash and just pushing up.
From there its very difficult to make progress w/o either taking the dash out, or coming in from where the stereo is. All the plastic clip on pieces (the grey inside liner, and about 2 or 3 more layers deep) all have clips on the top *and bottom*, and none of the bottom ones I could get off.
Here is a diagram showing clip locations, and possibly where the hidden ones are. I did not find a screw or clip in behind the gauge to hold it in, so that part is still a mystery.
Also included is a size comparison... Looks like a little custom work would be required to get my autometer a/f gauge to sit flush.