Small black marks on old surface rusted panels

[graham_fuller]

Hi all,
I am working on previously surface rusted panels. I have stripped the paint off these panels and polished the black marks with a clean and strip disc, I,have then used Septone rust converter. The question is have I done enough to now etch and undercoat the panel? Do the black spots need to be gone altogether? Will the rust come back after I have fully painted the panels?
Cheers,
Graham
Ps Happy New Year.