This part of the seat curve looks patched and does not look factory right to me. How should it look? How to fix?
IMO, depends on what you want to do with your T.
Appears to be an old repair, done years ago. And the doors have added exterior door handles, so your T has lots of older stuff happening, I really like T's that have stood tough, and been well used and modified by former owners
The correct repair for all that damage is to re-check the frame wood, see if it is correct too.
Then replace the entire back panel of that touring.
Wood frame details in drawing.
What it should look like.
Thought comes to mind on why that repair, are both sides of the seat back like that?
You might keep looking at the back rest, look for hinges or something, as maybe the seat back was sectioned for folding down.
Many a T has been modified that way for camping, folding down the front seat back rest to make a bed.
The other side is the same way patched but it does not look like it was ever laid back. There are dime sized rust holes near the bottom of the seat back.
I think I could fabricate and weld on new armrests if I had a paper or cardboard cutout of the original dimensions.