Replace whole thing there only $87
https://www.opgi.com/chevelle/1968/shee ... l/CH27102/Probably need these when replacing the outer:
https://www.opgi.com/chevelle/M240189/You Might need these too by the look of that Rust.
https://www.opgi.com/chevelle/PZ00629/And if your replacing the outer's its a good idea to replace the inner's so you probably need these as well:
https://www.opgi.com/chevelle/CH26957/The thing about rust is its almost always worse once you get in there, These pieces like to rust from inside to the out side! So even if you patch up what you think is bad 6 months later rust is back bubbling up through your paint again.
Another point I would like to make even though after market replacement panels leave a lot to be desired using them is almost always faster and easier than trying to make your own Panels and Patches when their available.
As an example I am going to buy two new Quarter panels from this company for a 70 Chevelle I'm working on.
https://www.opgi.com/chevelle/1970/shee ... s/0815132/ Just so I can cut part of the wheel well off on each, an area about 4 inches by 4 inches it may seem like a waist to many but Its just Faster and easier to make a nice Patch from them than try hand forming what I need.
Can I hand form what I need? Yes BUT The amount of hours I need to make what I need with the tooling I have which is extensive still exceeds the Price of buying the panel already done. "Picking my Battles" My time is better spent on Panels that are Very expensive or flat out unavailable. Plus like I said above once your in there Rust is generally worse than what you can see so I am guarantied to have enough panel to make a Patch from once they get here and I start surgically cutting the rust away to get too good clean metal.
I am a Big fan of leaving as much original panel as I can, I will always prefer a properly patched panel over a Cheap replacement panel ANY day! The Panel is only Original once and saving it is a Priority when possible! a Patched panel may not look as Pretty as a new panel BUT its mostly Original! and Original always fits better & looks better.
Just Like Panel gaps These older cars NEVER had Perfect Panel gaps why so many think they need to add metal or fill the gaps amazes me. Sure way to loose points in a car show in the Original category when Judges inspect the car. Unless you take your time to install and align the original panels without modifying the panel so there is no added filler metal or filler and even then you can only get close because these cars NEVER had perfect Gaps.
The factory never did this on the assembly lines it just takes to much time they would get it close and have a Tolerance with GO/NO GO Gauges to check and as long as the Go Gage would fit and the no Go wouldn't down the line the car would go.