Just prior to finishing skin riveting, I discovered that I had neglected to dimple the sides of the rudder horn brace which are riveted to the four forward holes of the skin and lower rib. Things looked very flat but I figured the horn brace should also be dimpled. The only way to accomplish this is to drill out the three brace to rib rivets and the four horn brace to horn rivets (which I had so difficultly set in the first place) I then for some unknown reason felt that the lower rib to horn brace and horn brace to horn holes should be dimpled/countersunk (despite the fact that I knew the callout was for 470 rivets)
I should have just put my tools down and called Vans- when I did the next day I was told that things would have been just fine the way they were. Although very difficult, the rivet removal did go ok and no pieces were damaged
The next day I re-riveted the horn brace including sneaking the four AN470 rivets back inside the horn brace.
Next time I will be more patient and also I will leave myself some "must finish this" notes as this error was helped by my not working on the project for many weeks and forgetting things