The assembly of the firewall is pretty straight forward, but today I needed to dimple and countersink a bunch of parts, and the directions don’t really tell you much more than “dimple and countersink the parts that need it”. So I had to read thru the entire section of the plans a few times, but after paying close attention to the diagram that shows which rivets are used to attach everything, it made more sense.
So, everything got deburred, countersunk, and dimpled.