My girlfriend's car had a nasty dent in the bottom of her oil pan, and everything was so dirty, I wasn't sure there wasn't even a leak there. Her transmission went bad & we found a used one on-line. During the job, I had the mechanic who was doing it "fix" the oil pan while he had the engine out. He did a really nice job of banging it out & re-welding the part along the crease he thought might be leaking. Then he said he re-positioned the drain plug a little lower, so more will drain out when changing oil. It turned out really nice.
So, yes, if you're willing to go to the time & expense, the pan can be taken off and either a "backing nut" welded on behind it or other repair. You probably could tap it out to a bigger size too, but you better be careful the new threads are nice & straight. And also be sure to clean any metal filings out if you do that!
__________________
|