Where did the spot welds go

Thanks guys I'm going slow. I'm making templates of where the bottom of the rear seat brackets go so I won't have to wonder where their proper placement is. I've made a coupe of mistakes by drilling all the way through that I will have to fix. I've got the sides drilled and across the back of the pan drilled. It appears that I will have to take the quarter window out when I get ready to fit the new pan. Even after I get the old pan out I will have a ton of clean up work to do. I guess it's my OCD kicking in but I just can't leave the other stuff dirty and rusty