I saw the thread you mentioned, it did look a poor job. To repair my door in the pic I used offcuts from work. I was lucky with the sections as they were a good fit and Galvanized. Front doors are my next job, they seem to be in better condition than the back.
Hoping to go on a vehicle restoration course soon, have applied for a grant from the John Cope trust.
If it all works out I should be in a better position to work on my Landy.
My Son lives in Badersfield so I use that road quite a bit myself.