All the joints around the Muffler tunnel have to be sealed with Proseal. Messy old job.
The Firewall assembly is then trial mounted to the Muffler and floor panels. MAJOR COCKUP. I had left the curved stainless steel sides of the Muffler tunnel on the wrong side of the centre panel. I removed about 14 rivets from the centre panel, removed all the Proseal, pushed the curved sides into the correct position and replaced the rivets with the help of a Rosie the riveter (she did a great job on the gun). All good again but a waste of valuable building time.
All the gaps have to be sealed before riveting. This is a job that will take a bit of patience and a few hours so will have to wait. In the meantime I riveted the Cover Bases on and countersunk the battery box. The rear holes of the box were inaccessible even with the extended countersink so I countersunk them by hand.