Started with removing the bottom skin after reviewing the drawings for anything I might have missed and checking all rivet sizes. The bottom skin is mostly AD-3's with a 20 or so AD-4's. There are some bolts in #12 holes and a I think 6 big flush screws. So all the AD-3's and AD-4's need to be dimpled.
About a half hour in on the bottom skin deburring, there was a power outage at my house. I almost gave up, but the sun was still out and there was some light for working. I got the head light out and just kept going. Pretty quick I discovered the two rear rows of holes hadn't been drilled yet. I still had a full tank of air so I was able to drill them out pretty quick.
