It's too late to do it. As mentioned, I'm not re-starting the save.
I have created the third kit (icon, jersey, shorts, kit & text) with the in-game editor, so I have the generic kit showing on the Club page..........but it doesn't allow for the graphic to work since I didn't create it in the pre-game editor. Obviously had I known this before I started my save I would have created it in the pre-game editor. So if I ever start a new save, I'll be sure have it in there but I doubt I'll ever play as Valladolid again.
Merry Christmas !