Kind of new to this, I don't know if you received the message from Monday?.?
I don't know what the rest of your quarter looks like, but if that's all the damage as seen in the photo I'd pick and file it.
Not to say anything bad about the guy who said, that area is a hard place to sand. I've been doing this for almost 30 years and that little curve on the quarter is easy if you use the right tool.
From what I see in the photo it would be a lot easier to pick and file that out and lead it. Use a file that is half round "kind of U shaped".
You can work most of it out before you put any filler on it be it lead or bondo.
If you think bondo is bad it's not, it's the A--holes that think it's a car in a can and they think they're a famous sculpture artist. If you work your metal and use it to get out minor imperfections it's fine.
With the primers they have now you can stick, I guess I should block out a lot of imperfections.
What I meant by stick is I never sand primer with a block, I use a paint stick and wrap the sandpaper around it and stick it out. You don't have any square edges like you do with a block so you won't have any surprise sanding lines.
Back to your quarter panel, if that seam that shows in the photo goes from the door jam to the tail light panel, then that's an aftermarket quarter. And if they don't make full quarters for the Camaro's yet, then work with what you have on the car. Because the aftermarket quarters that run down that body line are a pain in the ass to put on. I've had to put them on and that six foot weld (I don't care how much you jump your weld around) that crappy Taiwan sheet metal is going to warp. And if the try to tell you that their sheet metal isn't made in Taiwan, they are full of S----.
Let me see some more photos.
If you think I'm a whack it and pack it body man I'm not. Over the years you would be amazed on how much bondo I've taken off of old muscle cars,Porsche's,Mercedes,Jag's,Rolls,Etc...It doesn't matter if it's a hundred thousand dollar car I've knocked off other body shops bondo that was 2 inches thick or sometimes there isn't even sheet metal behind it.
Go to my my space page and check out the 69 SS Chevelle I did back in the later 80's or early 90's. The Rt. Quarter just behind the door, when I looked down through the quarter glass, there was an arm of bondo coming through this hole that was about 4 inches round. That was when you had to find used quarters because they didn't make aftermarket ones.
I don't do that My Space to often but the my page is under jeffspaintandbody
There a couple of photo's of 67 RS and 70's Lt Camaro's.
If I can help you let me know my email is
[email protected]
Jeff