I had that same issue with both quarters on my car. What I saw was that the unwanted body line should have been the actual break where the quarter turned under the rocker. I cut that pie shape piece out and welded the bottom back on and mine fit perfect then. Had to do a lot of small mods to these quarters to make them like the originals. They are far from perfect but thank goodness they offer them.
View attachment 1715810231
View attachment 1715810232
View attachment 1715810233
View attachment 1715810234
View attachment 1715810235