I was just quickly (first mistake) working on the elevator trim tab and thinking how relatively small the pile of ruined parts was aka the pile of shame and mentally high fiving myself when I managed to screw up the part I was working on.
The elevator trime tab needs to be dimpled to take 426 rivets but the top flange of the trim tab spar needs to be countersunk so that it presents a flat surface to the hinge when attached. I knew this and had read ahead so even took a permanent marker to write a warning for myself on the upper flange of the part....then I proceeded to merrily dimple right over the bit I just wrote on.
.....another order placed with the Vans online parts store for a replacement and also ordered the trim servo hatch replacements from my earlier screw up. Happy days!