LOWER QUARTER PANEL TO ROCKER PANEL SEAM

I have an original paint '70 Hamtramck Duster and the seams are neatly leaded over and smooth, I also have an original paint '74 Duster made at St Louis and it has the seam visible where the rocker meets the quarters (kinda unsightly).... I think this was more prevalent on the '73 and later cars....why? I don't know. Maybe to save money/time.
You can see the seam in post #32 of my air shock disccussion. Its a '74 Golden fawn Duster. Air Shocks | For A Bodies Only Mopar Forum