How is the Firewall Attached?

[53OlderThanMe]

My late 31 Roadster had an aftermarket firewall that I want to swap for an original late 31 firewall I obtained. I see how the top is mounted to the gas tank.

1. How are the firewall sides attached to the cowl? Spot welds?

2. How is the front sub rail extensions attached to the bottom of the firewall legs?

Thanks

 

[jw hash]

you say you have an after market firewall in there now, so it is no telling how they attached it in there but the original was put together as follows.
1. the side cowl panels are spot welded and one rivet down towards the bottom
2. the sub rails and lower cowl are spot welded and riveted
3. there is a brace on in the inside right at the cowl light that is riveted
sometimes finding the spot welds can be tough.
for the purpose of saving the body from any further damage do most of your drilling and grind on the firewall.