I disassembled and deburred all of the channel holes in the cabin frame. I then started working on countersinking all of the necessary holes. These are the ones in the channels that are used to rivet on the splice plates.
I also did all of the outer holes along the forward channels. These are a little trickier since the curve prevents using the countersink cage to set the depth. Basically, these all need to be done freehand which makes these holes fairly time consuming.
