there is a hole, maybe 4 inches wide by maybe 1.5 inch high on my floor pan, jus wonderin if it would be smarter to put in a whole new section or just cut the bad section out and put a patch and rivet it in. also im not doin a top notch restore because i never plan to sell the car and originality and fine detail really isnt so important to me.

 

Rivets arent a good idea. welding in a patch is a good idea. It doesnt have to be pretty or perfect, just water tight. Doing the entire floor isnt needed if the rest of it is ok. Pull out all the carpet and sound deadener to have a look. If its real bad, you can do one side or both. You can even pick up a cheap 110V mig to do the work, but practice on some scraps first. Its not that tough to do.