Dick, Jack and more than a few should be able to tell you about any differences between the models.
As to paint schemes; Quite a few stations when they updated their exteriors to a more modern look would sell their older pumps to independents and/or "Mom and Pop" facilities. This happened quite frequently up through the late 70s, early 80s, before the EPA put their foot down.
It is not uncommon to strip the paint off of even newer pumps and finding different paint schemes depicting several brands. At times one will find decals from several Oil Companies also, as the pump and/or station went through these changes.
