Restore some vanillia industries to a FIRS fork

[jimbob]

I would like to restore 2-3 of the vanillia industries to a fork of FIRS (gold mine, bank and print works)

Hunting around the source code I can't seem to see where the vanillia industries are turned off / replaced, would they come back by just not overwriting their ID? or is something more involved required?

[Eddi]

or you could just make an addon grf that only contains one line to make a copy of an original industry, and not mess with firs code at all.

[jimbob]

What single line would that be?

[Eddi]

tried this one?

Substitute industry type (08)
Substitute industry type. The first assignment of this property copies all properties of the old type to this new type.