Changing 67 Fastback rear valance

I am replacing the whole thing after I swap out the trunk pan. The reason for the "excessive" welds down the middle is this part ties to the trunk pan all the way across and is essentially what holds the frame and body on the unibody together. If you cut the valance apart in pieces to get it out then remove what's left leaving the rest of the metal intact that "tabs" into it. You can temp fit and clamp the new one in place, then using a silver sharpie outline where it all overlaps to the new valance. Take the valance back off and drill a bunch of nicely spaced 1/4" holes. Clean up the panels that "tab" into the valance and spray them with a weld thru primer. Then fit up the valance again and use self tapping screws thru every few of the 1/4" holes to draw it tight. Once your certain it's how you want it to be, weld up the 1/4" holes tying the valance to the angle tabs. Then remove the self tapping screws and weld those holes up too. The taillight bucket frames overlap the valance. You leave those intact. If you can see the spotwelds from underneath after cutting away the main parts of it, you should be able to use a ball rotary file on the spot welds from underneath the taillight bucket frames and release the rest of the valance. I am currently doing a trunk floor replacement. And am in the process of a total floor reskin on a 69 barracuda. I will be doing a complete rear valance replacement next. If you look at the last few pages of pix on 67/68/69 cuda dilemma you can see exactly what I am talking about with the 1/4" drill holes, screws etc.