they are all the same front bumpers on 74 and 75 lesabres and electras and estate wagons. just have different inserts in the lower holes to match the grille. some have full bumper gaurds and some dont. depends on the car options. rears are a whole other story.
here is a pic of each from some current ebay ads. the grilles/headlights are different but the fenders, hood, header panel and bumpers are the same. fenders for an electra have a larger cutout in them for the quad port holes as opposed to tri port holes. some fenders have cutouts for cornering lights if opted.