Pictures i can give you by the bucket load, look at project Paddy in my signature. That is a complete rear end replacement from the rear window down.
Now as to that floor, i'm sorry but that floor is toast. If its pitted its thinned and i bet underneath will be bad as well.
Personally i would bite the bullet and buy a complete floor assy inculding crossmember and heelboard.
With it being a 64 i would defo visit M Machine's website. However please bear in mind they sell Heritage Magnum and their own pressings.
Your biggest issue here is distance and getting the panels you need. I would say talk to Doreen but being in Oz may make that expensive.
Go from page 19 onwards.
https://www.theminif...rebuild/page-19