Thank you for the well wishes for a speedy recovery. While i am a captive audience i will help as much as i can. Its Prob bad sender for the water temp. Its prob shorted internally to ground. If the IVR was going bad fuel level and water temp would both peg or go to empty.
For your fuel level gage, unplug the wire at the sending unit and run a jumper from the fuel tank sender wire directly to a body ground only long enough to see if the gage deflects to full. If it does go to full, then you may have a bad sender, or a sunk float. I have seen these old brass floats develop pin holes and fill with fuel. The repop senders are not as accurate as the originals, so if its that , i recommend removing it, cleaning it up with some tarnex, or CLR and ohming out the sender with a meter and making sure you get a variable resistance from full to empty. I believe you can buy a new float if thats whats needed, a new filter sock, and a rubber gasket. If you can save your metal sending unit retaining ring i recommend doing so. The repop ones dont fit very well.
When back there, look for a stamped sheetmetal metal jumper that goes from the sending unit tube and attaches to the body fuel line this is the sending units ground. If its missing the gage wont work either. Check for this strap at the gas tank first. If its missing make a temp jumper ground wire from the fuel sender to body ground and see if gage works. If jumper strap is there, unplug sender wire and jump that to ground and see if gage deflects to full.
I have about a 20 test lead jumper wires with alligator clips on either end in my tool box. I bought em at radio shack premade. They come in red, white, black, yellow, green. 2 leads in each color 10 to a package. Way cheaper than you could ever make them.
See pix below for sender ground strap, and position on fuel tank line.
View attachment 1715093131
View attachment 1715093132