The joining plate had 1 hole that was misaligned with the side rail angles which needed some attention.
For the side rail joining plate CF-PLT-005-X-A misaligned hole see Side rails.
This misaligned hole was not present in the outside side skins.
Since the hole is already close to the edge I didn’t want to up-size the hole to 4.9 mm.
I decided to remake these plates.
From 6061-T6 0.090″ ~ 2.3 mm aluminium I cut the new plates and sanded the edges smooth:
The misaligned hole match-drilling:
I made a third plate that can be used for match-drilling the side skins.