When can I rivet F-1281?

[kritsher]

...that's the lower l/r tailskin.
On page 10-07 the instructions state to leave most of the holes open. Nowhere does it say to go back and rivet them. Now, I'm on page 10-09 and it says to rivet F-1280, the side skins. I assume I can also rivet the lower side skins at the same time, but am I missing something?
Thanks.

 

[Gagarin737]

Page 10-07 step 3 tells you to rivet the F-1281 L&R to the bottom skins. The text "Leave open, both sides" considers the upper flange of the F-1281 L&R, the rest of the holes will be filled with LP4-3.
The masked rivet holes on the forward side stays open until joining the tailcone with the fuselage. The aft open holes are for the aft bulkhead.