Found the same model radio on FB marketplace with the hardware I needed so I scooped that up and found out it works after testing with a make-shift speaker set up.
I installed a new telescopic antenna and ordered a replacement under dash speaker to have in the truck.
I also crossed a few more items off my list:
- removed the seat belts and gave them a proper cleaning - they are blue (faded) again (although I didn't get any after pix) - may need to update these when I get the carpet, console and bucket seats installed
- fixed the squeak noise in the heater controls (metal on metal noise)
- while I was in there, I removed all the heater cables, lubed them and fixed the bent wires/levers for easier operation (way better now)
- installed a better set of interior color-matched door handles I picked up on the forum over a year ago
- modified and installed a NP205 shift boot and ring for my Muncie M22 by using a Hurst adapter to prevent the boot from tearing