Stators with a just a narrow band showing are used on the revised squareback.
The revised squareback case is different and off the top of my head one of the brush holders and brushes is different.
They should know those two styles shouldn't really be interchanged. Yes it fits but the field draw is different and if that's something you want to try, cool, that's hot rodding. But IMHO when a replacement part company says an interchange is OK when there actually are differences that are potentially damaging, that's not cool at all.