@
Sturuss -
sometimes one strips and paints/powdercoats and restores to original
sometimes one preserves by stopping all rust, waxing and re-building; or touch-up and re-decal
sometimes one reassembles with original or era appropriate parts, or modern components
most times some combination of the above.
There is no right or wrong - there are no ethics in vintage bike building. You just have to know the exceptions. What '73 Italian?