Hi,
When replacing the door Qtr light seal you have to consider the condition of the window support. The window support plate attaches to the door by 2 screws and usually they are very corroded depending on the condition of the seal. They are a rare item to find in good condition, even from a breakers yard. The one in the picture is the drivers side panel and you will see it is shaped to the contour of the door. I was lucky and managed to get the last 2 from grub locker. This one is pitted but can be reused. Fortunately the rust is only confined to this piece and not the door frame, mainly because it sits on a bed of mastic. To complete the qtr light seal replacement took me about an hour and this includes taking off the door card. A little more time was given to applying wax oil to the door inner panels.
Regards
Alan