trunk lid skin - how attached?

I am working on a 69 Dart. I pulled the trunk lid to strip and epoxy this weekend. As I was stripping out the old seam sealer around the inside lip (had a bit of surface rust in spots, needed to media blast), I noticed that it appears that the skin was tacked on. I expected a spot weld, but it is held on with a teenie tinnie little tack weld at several places around the skin. Is that right? They dont look terribly strong, but if they are original, I wont mess with them.