Is a coated steel required for your intended purpose? Probably not. Even if needed, there are probably alternatives…such as tinning the steel as needed to allow seams to be soldered.
Industrial methods and materials and hand crafted methods and materials often differ
as much as day and night.
Article on how a welder duplicated a rusted out gas tank on a rare rare rare car…welded it
an exact copy in stainless steel. Not many could afford him, but, those who could were pleased.
Louis.