I continued today with more tailcone riveting.
First, I finished up the riveting of the side skins to the stiffeners.
I back-riveted as far to the aft of the tailcone as I could and then switched to a mushroom set and bucking bar.
I then riveted the side skins to the bulkheads (except for the forward bulkhead) starting just below the longerons and working downwards.
I back-riveted most of these, including along the curve at the bottom of the side skins. For these I tilted the tailcone so that the skin was tangent to the back-riveting plate. This worked really well and kept the tabs tight against the inside of the skins.
Almost done with the current page! I still have to rivet the side skins to the bottom forward skin and complete the remaining rivets at the aft of the tailcone. It is quite light now that that clecos have mostly been removed.