I mixed up some Bondo, about a third of a can. Using a 4x6 spreader, I evenly applied it to cover the area.
Here's the driver's side. A few low spots remain but the welds and the splice are covered. Just a little more Bondo needed here.
The curve in the quarter glass is correct.
Here is the passenger side. Low spots gone, no bulges. Even and smooth.
This is after I used the surfoam, a grating tool used before sanding to expedite finishing.
Not done yet, but looks pretty good.
Just some block sanding, a little glazing putty, primer, and let's see the final product.