Today I finished up the tank attach nutplate countersinking on both spars. I still have to deburr and alodine all the holes, then they'll be ready for nutplates to be riveted to them. I also have the (thankfully fewer) nutplate countersinks to do for the inspection covers. In the next pic you can see the backplate I used for drilling the countersinks at the inboard end of the spar. If you make it narrow enough, you can flip it over to use for the other side of the spar (as they are mirror images of each other), then it just takes one piece of scrap to do all the inboard parts.
Here's a (not so good) picture of the countersinks on the left spar. I can already tell that the wings will be tedious in many places, as there is a LOT of repetion throughout the whole structure.
