Finally got around to working on the driver’s side floor pan:
You can see some of the holes in the floor pan:

Cut out the bad area:
Used the cut out as a template for what to cut out of the half floor pan (which was included with the car)
At first, I cut out a larger area than what was needed:
Notice the bracket which is for the emergency brake cable. I believe I will have to remove this and use on the new piece:
Checking the cut out piece:
Prepping the top side with 80 grit… Checking for other rust and preparing the metal for welding:

Then ready to use some 36-grit to remove the last little but of metal:
This is a bad picture, but it does indeed fit. Need to clean the metal on the patch piece and bottom of floor on car before welding. Also have to change the welding wire in the welder for this sheet metal. Once the metal is prepped, have to get a second pair of hands to help me get it in place for welding.

After this is welded, there are a couple of small areas that still need patching (smaller than a nickle). The the welding should be complete!