EDIT: Looks like the comment I posted (and deleted) regarding your PRP seats was a little out-of-date. You and your pops are making spectacular good progress. It looks like you bought the PRP seats? Do you like them so far?
Regarding new battery Terminal and fusible link set-up will that...
FYI...you can drill 1/2" to 3/4" diameter holes into the bottom of the expensive SOR seat foam to make it tolerable if you want to go the OEM-like route. Maybe better to just get different seats if you are looking for comfort.
@BurntToast : You did a spectacular job removing the old carpet and bitumen and you'll be pleased with your new carpet.
I bought my carpet in early 2021 from DNP and at the time he provided a tip sheet which recommended 80mil Noico as the best value. My OEM bitumen and floor was in great...
The OEM grey dashpad was still available from Toyota last year. I bought one from All American in ABQ, but had to paint it brown to match my truck. It will make a big difference in your truck and who knows when they will sell out.