Stripped most of my 33's interior out to check the rust damage of the floor.
Here are the spots that needed to be welded (were rusted through):
Had some rust in the seam connecting the middle and front part and some welding had been done by the previous owner to where the jacking point is (was). The drain "plug" was welded shut by the previous owner. also I did see some rust below the pillar structure below the drivers seat, but can't get to it before I can get the car up and the anti-rust compound taken off.
Passenger side floor:
The drain plug was rusted away (almost nothing left) and a small see-through rust damage at the seam (same as drivers side). Bought a new plug and welded shut the seam. Same kind of rust damage below the seat as in the drivers side.
Drivers side back floor:
Small rust hole just behind the front seat (at the door side) and a HUGE 10x30cm hole on the right side of the floor (almost at the center fixing of the drivers seat). Drain plug was welded shut by previous owner.
Passenger side back floor:
Almost all of the right side front seat fixing was gone. Needed some clever welding to get it sorted. The floor itself was in good condition. Drain plug was welded shut by previous owner.
Huge rust damages to the shock absorber chamber, both inside and outside. Few randomish see through spots at the back floor and below the spare wheel. Drainpipe below the spare wheel was in OK condition, so just gave it a nice phosphor acid path, and it's as good as new. Wheel arch on the drivers side has some issues. at the top ... some of the petrol tanks pipes that come in the car, have had their original hole enlarged by rust. Also the tanks fill pipe fixing spot has been corroded through and seems to be held together by the anti-rust compound.
F.Y.I. This is a left hand drive car we are talking about.
Got MOT this week and have absolutely no chance of passing it (not because of rust as it's "all" fixed). I'm hoping to get the 1 month time to fix things, as some of the parts I need haven't arrived yet