71 dodge dart swinger. 360 engine

It does have a fender tag but I won't be able to check it till the weekend ( traveling at the moment )

Trailbeast how did you fix the sail panels?

Thank you for the info guys

First thing is pull the chrome so it doesn't get messed up. (I left the window trim and just taped it up good.)

A wire wheel on a grinder takes that old stuff off pretty fast, and gets down to clean metal.
Then I take a small chisel or screwdriver and pop the seam up so I can get under it as much as possible.
I soak it with Eastwoods rust encapsulator getting as much as I can up under the seam with a brush or foam brush and tap the seam back down only below the rest of the panel surface so the filler material can get up under it so it has a really good area to hold on to.

I rough up the metal down in the valley and a couple of inches out on top and bottom of it with a grinder wheel and start filling it with Bondo Hair (fiberglass resin with strands in it)
Until I have it pretty much at the level I want the surface to be.
A credit card stuck down in the gap between the body and window trim works well to let you get the gap filled all the way to the body edge (and make sure it does get all the way in there.)

Once that is set I use Bondo Gold Professional to get the roughed in surface and curves.
I use a 4"x4" electric sander for the shaping of the curves.
Spot filler is used to finalize the surface and get it ready for primer and a little block sanding.
I use as much of the fiberglass to fill and shape as I can and only use the Bondo to get my top surface smooth and straight.

That's about it.
It takes me about a day per side with set time and primer drying time and a coat of paint over it.

Make SURE the ends on the seam are filled and sealed or water will get under the filler.
One thing to check out is at the bottom of the drip rails is a gap between the rails and the body that lets water drip straight down between the body and the glass and I like to fill that gap so the water gets dropped on the body and runs forward to the door gap, or down the rear fender and off.