[OrrieG]

You hit it 4 vs 2 headlights and associated body changes. If you look closely the 58-59 hood and fenders are 3 inches longer to accomodate the deeper grille and the hoods mount differently than earlier models. Notice how the trimline above the front fenders follows the back edge of the fender into the bottom trim line; 55.2-57 are plainer. This reflects the deco type changes that were also showing up in the 59 GM cars. In 58 you could get a step side, Cameo or Fleetside (first year) bed, all interchange on the same frame. The FS will fit 55.2-57 but purists heads explode when they see them. You didn't mention GMC but the grilles went even further over the top, in a good way. Dash in GMC's (except fleet option) are different without the iconic V shape dash cluster. Mechanically 55.2-59 are pretty much the same. Most common parts are available, just view a LMC or Classic Parts catalog.

Your wife has good taste, follow her lead....