Floors
As you can see in the pictures above I have several places that need to be repaired. Front Passenger Floor 2'X2' Front Driver Floor 1'X1' Rear Passenger Floor 4"X4"
Front Passenger Floor 2'X2'
This section was the worst.  It had quite a bit of rot.  It looks like the water came in from the windshield.  When I removed the windshield I found out that the adhesive was not attached to the car.  The adhesive was firmly attached to the windshield but the other side looks like it came loose and allowed water to enter in and rust out the floor.  There is also a bit of rust in the roof in that same area.
Cutting   To start the replacement of this panel I took a marker and marked around the perimeter where I wanted to put the replacement.  Afterwards I cut out along the lines.  Then I took the parts I cut out from the car and used it as a template and marked where to cut for the replacement panel.  I cut the replacement panel out adding about an inch to the overall dimensions of the pan.  I used a full passenger floor pan that I purchased for another project.

Welding

  Now I  I took the replacement panel and fitted it to the hole that I cut out in the floor.  Here I took my time to trim the panel until it was as close to perfect as I could get it.  I decided to lap weld the panel since I did not have the best welding skills and since I could weld it from the bottom to seal the joint.  Like I said before I do not pan t make this a show car and also since this is a floor I really don't mind  seeing the welds.  I earned a valuable lesson on how important it is to appropriately clean the area before you try to weld.  The weld is  so  much better when the areas being welded are properly clean.  I took at wire brush and cleaned the area completely.

  Once I had the panel where I wanted it I started welding.  I skipped around welding a little at a time so as not to warp the floor.  Soon I had it welded in completely.  I want to wait till I get it welded from the bottom before I grind down the welds.  I plan to put the body on a rotisserie and weld it from the bottom after I get the floors done.

Front Driver Floor 1' X 1'

Cutting

   First I marked out where I wanted to cut.  Since there was still a partial piece of the shifter hump still spot welded to the tunnel I need to remove that before I cut out the right side of the tunnel.  I took at die grinder and sanded the hump to reveal the spot welds.  Then I took a spot weld cutter and  removed the welds.  After I removed the spot welds the shifter hump just fell off.  Now I could square off the hole where I am going to weld in the replacement panel.   I took a 4" grinder with a cut off wheel and cut along the lines I made.  Then I took the die grinder and sanded down the edge so I could get a good weld.  Now I could measure the hole for the filler panel.

Welding

  I took the measurements from the hole and laid it out on the floor pan.  Then I took the grinder and cut it out.  Now that I had the rough size of the opening I took some snips and trimmed the panel so it would fit the opening.  Here is another case of how I would do something differently if I have to do it again.  If I had to do this again I would tack the piece on one side and use a body saw and cut through both panels about 4" at a time, weld a spot the cut 4" again until the panel is welded on all sides.  This would minimize the gaps and make the fit much better.  I did not think of this procedure, I found it somewhere on the web.  I really sounds like it would work.
  I took the panel that I trimmed and tacked it into the hole I cut out.  I started on one side and tacked it all around till it was completely welded in.  Then I took a grinder and ground down the top side.  I will weld in the panel from the bottom when I get it on the rotisserie.  I still need to get a new shifter hump and weld in on top and cut out the proper size of the opening.  I will do that later.

Rear Passenger Floor 4"X4"

Cutting and Welding

  This section was under the passenger side of the rear seat.  It had a few holes the size of an ice pick.  I marked a 4" X 4" square where I wanted to install the patch.  Then I used a 4" cutoff wheel and cut along the lines.  I then took a die grinder, sanded the the edges, and welded it in.