Some small fixes to the floor section were done and shooting rivets where possible.
First fix is to round the sharp corners of the 2 flanges where the outside skin will be attached.
Before:
After:
Next was drilling 2 missing holes:
This was easy with a strap duplicator:
To be sure no rivets need to be removed when attaching the firewall I did a test fit:
I coated the steel parts with Ardrox:
Next was shooting the rivets where possible. For alignment of the AN5 holes for the engine mount I used 2 bolts:
In Onshape I created a drawing for the Rami AV-74 transponder antenna so I could enlarge the hole.
The antenna will be mounted to the bottom skin with a doubler. The hole in the top skin needs enlargement to have access to the 2 studs: