Installed the gusset for the front bulkhead channels and final drilled. MatchDrilled the #30 holes using the bulkhead channel into the cabin cover on both sides.
Final drilled #12 the channel and the cabin cover.
Clamped the cabin cover to the underlying F1015C mid cabin decks and drilled #30 the holes into the cabin cover and F1015C mid cabin decks. Then final drilled #19 (NOT #12). Clecoed all in place.
After that using an extension i countersunk all the holes to the proper size.