Aligned the pre-drilled rollbar brace replacement with the skin at the baggage bulkhead, and match-drilled the 5 skin holes to #30. Cut a 1/8" plate of AL, and match-drilled to the brace holes. Then match-drilled the remaining holes in the plate.
Clamped in position, used a screw-cleco to fasten securely and aligned side brackets.
Disassembled, deburred, and scuffed with ScotchBright. Re-assembled and checked fit. Stopped for the night ...