Yesterday afternoon I decided to:
A) investigate how hard it will be to get the turn signal module out
B) Explore the extent of the damage to my plastic substrate.
Results: gotta get a steering wheel puller if I want to turn left ever again. Also, it appears that somebody in the dark history of my GTU took apart most of my dashboard without first removing ANY screws. Almost all of the screw-mounting tabs in the yellowy plastic substrate are broken, even some of the little front speaker mount tabs! This could be related to the symphony of rattles and squeaks I hear from my interior.
So I decided that because this is no pristine dashboard and interior, it will not be sinful to fabricate and attatch custom mounting reinforcements out of whatever junk I have lying around. Of course, I have high standards of durability and safety in all my Poverty School of Engineering projects, so there will be no flismy band-aids or sharp baling wire.
After 2-1/2 hours of killing my knees and contorting my hands, I managed to secure both sides of the panels below the steering wheel to the dashboard's steel frame with small bolts and large washers. I even peeled back the soft vinyl so as to hide the boltheads. No such luck on securing the gage-cluster cover to the top of those panels, but a little metal tab with a screw and a bolt in it isn't too bad - but no car shows for me.
Today (if I escape the job on time again) I will attack the passenger side of the dash, and maybe check out the insecure passenger seat.