I had the same problem on my 69 camaro the reason was I had my quarters replaced around 1980 GM still sold quarters but wheel wells were already discontinued for the 69's. The repo houses were selling a cheap fix, it was just the lip area, some said it was the outer edge of a lemans wheel well which has a similar shape, I dont know but it didn't fit well at all so when repos became available I too wanted mine changed but I seen no way of getting it in in one piece, thought about putting it in in two pieces, after looking and trying different ways it just wasn't going to happen. I figured if I could get it up in there, in the position that it goes, and just slide it strait into the quarter it would work, but what kept that from happening is the is the inside lip its under the inner and keeping it cocked. So this is what I did with good results,I cleaned all the sealer out of the seam where the inner and outer meet, I cut the old outer well out leaving about 1/4 inch outside the seam, then I cut the inside lip off the new well leaving just a little so it would turn up into the seam I was then able to roll the well right up in there and I tell you, it took a little pushing, but when it snapped in I dont think I could have got it back out if I wanted too. I welded it in the seam and ground it smooth to look like sealer
