Thanks for all the replies, I really appreciate the feedback

Re the condition of the floor. I just know the floor is rusted through under where the rear seat cushion is located, on either side of the tunnel. If memory serves me, its about 2-3" wide or so. I would assume that whole area has an issue, but really never looked to deep into it...just knew that it would need to be addressed. SO to sum up, I just know I have a bad section of floor and not sure how much other rust I might have (floor wise).

Re firewall condition - outside of the peeling paint, it doesn't have rust. Its in good shape, just looks ugly.

Rustaddict brings up good point that I did not really think of. The rear post is just anchored to the floor.

Thanks for the welding tips Laszlo & Rick_L. I wanted to weld the seam of my 2 piece frame, so that would give me some practice welding so I can move onto practicing welding thinner metal.

After reading I'm feeling a bit encouraged to try to tackle this.

Love to hear more opinions, ideas, thoughts