This step is just to rivet the tailcone Shear Clips to the Baggage Bulkheads. Two little rivets per side. The plans seem to make a big deal about these Shear Clips, but for the life of me I cannot see what they do.
If you put the rivets in from the rear you will need to climb into the "boat". The alternative is to put them in from the front, in the little recess that will shortly be covered by the remaining corner skins. I elected to put them in from the front. I'm still not sure which is better. All I know is it took ages to get the holes lined up and the rivets inserted, in a restricted space.
Picture 1 shows the starboard side corner recess, looking aft.
