After removing the cabin top, I completed the match drilling of the backing strips that are used behind the flanges.
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_0327012504448742173732336031.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_0402392633674442745186708958.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_0402454801462256176388951804.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_1602433153859221359041657290.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_1602486867176975364045699219.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_1602536754871163280396456656.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_1603119053724245651229851513.jpg)
I then removed, deburred, and primed them.
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221001_1631069275213218442160196677.jpg)
The holes were then countersunk for the dimples in the skins.
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221002_0208140655422050274000387004.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221002_0208261757922335435135040257.jpg)
![](https://airplane.allanglen.com/wp-content/uploads/2022/10/pxl_20221002_0208315174605379388053331648.jpg)
I then dimpled the side skin holes that attach to cabin top.