Fiddled around with non-firewall steel parts that I had painted the other day just to check them out for quality etc.
Spent time digging-out all firewall parts. There's 16 total. I could not find one part, C75-F8-9. I could find C75-F8-8, and C75-F8-10, but no -9. Couldn't even find it on the plans sheet. Looked everywhere. I know I inventoried everything correctly, so I went back to the inventory checklist in my office. Hmmm.... No -9 was even listed as available, so my count was correct.
Once that was complete, I deburred and de-labelled all 16 parts, then cleco'd together.
There is one L-angle stiffener that I have to fabricate, so that is not done. At this point, I can make that part and start riveting the firewall together.