As a kid of 80's many of us drooled after these:
Of course back then, our country was struggling at shadow of big neighbouring country and such seats and handlebars were banned rather quickly, it of course just increased drooling after those bicycles for young kids that saw them on tv shows.
One can see how Frank's design is kind of evolution of that design, just going higher with body instead of rising handlebars and MetroMPG's bicycle has that laid back attitude carried over from such bicycle of 80's.
In reality there probably is no relation, but customs have been around as long as bicycles have been common, I believe.
My best attempts with corrosion protection has been zink (spell checker fails to recognize, but Zn, I think word was zink?) primer, I apply it before welding as many of those say they are ok to weld too, just weld outdoors to avoid zink fever, great thing of applying zink primer before is that you actually get good shielding on places which are unreachable after welding.
I use that as poor man's powder coating, well it needs of course strong surface paint too on top of it. Might be worth to experiment with it.