A mess.. sheetmetal nightmare

[Mgicm]

Hi everyone
So I ripped off these replacement panels on my 51 AD which were put over the original floors and of course found a mess. Some of it I expected and some I did not. My issue is that the rust extended into the kickpanel area. I am trying to figure out what it SHOULD look like. Does anyone have pictures of the inside of the cab, no floor or maybe just before a replacement floor panel is put in? I am trying to see, specifically the passenger side, what it should look like in the area where the rocker ends, floor support and the kick panel. Is there a replacement sheet metal piece that can be purchased for this area? It is not even the kick panel I am having issues with but behind it..the part that is seen when you take fender off. Will try to get a picture.

When welding in the floor pan, is there a best way to do this? Should it be a perfect fit or ok to overlap just a bit with seam sealer? Looking for advice on this.

thanks!