Finally had sealant (tank doubler mod) available to complete this task.
Covered rivet heads on firewall stiffener, and at outer edges of firewall shelf. Also filled empty holes in upper firewall. (steps 2 and 3)
Drain valve and gascolator is already installed (not safety-wired yet). Radiator hose clamp not yet installed. This step 4 is considered complete since additional work is required in this area later during engine installation.
