I did a little more digging and found the spot welds on the back side in the wheel well. They are very easy to see there after scraping off the underbody coating. It’s really interesting bc they are completely invisible on the outside. I heated and scraped and there’s definitely no lead on there. They must have sanded this edge at the factory to hide the welds.
It would have been nice to separate the parts at this seam but that’s not possible as I can’t drill out (or even access) most of the spot welds from the back side.
The new plan is to cut the fender about an inch away from the seam. That should give me enough room to get a dollie back there to planish the welds after I weld it back on. Not ideal as I’ll have a lot more weld on an exterior surface to deal with.
