Cab construction question (elec. ground)

[IdahoMan]

Hello.

I will putting 50A Max sockets behind my seats and have a ground question.

How exactly is the cab grounded? The one place I know of is the bolt on the firewall where it is connected via a braided strap to the back right-side of the engine. But as far as the cab's construction goes, how is it assembled so the whole thing is grounded and at the same time not a rust-risk (if the cab is made of seperate pieces, the bare metal has to be connected electrically somehow)? For assembly/repair is the cab welded, then seam-sealed, then painted or something like that?

Below is the speaker corner where I would like to put a high-amp ground bolt. Will that work? (Yes, I'll be upgrading all my grounds)

Thank you.


Sincerely,
IM