Patching Marla’s floorpans

Here are some small holes I have in the floorpans on marla. I, very shittily, tacked together some exhaust that I’m going to have to redo as I become more versed in mig welding. I’m hoping to get away with patching these pans rather than replacing simply because I’m cheap and they’re going to be covered in carpet anyway (someday).
Here are the spots I’m looking at. These are the rear passenger seats.



You can see in the far left one there’s a pretty big hole. The holes further up are old drainage (?) holes.