Heater box resto detailing question

[66FBCharger]

I looked through a lot of threads and did not find an answer to my question.
I am preparing to restore my heater box for my Non A/C '70 road runner. I am restoring the car to a concours level (correct plating, etc.). What should the weld studs that attach the heater box to the firewall be plated? Do you have the whole plate plated with the studs still in place or do you remove the studs and plate them or do you just replace the studs? If you replace them, where did you buy them?