Rabbit is what the 1st gen Golf was named in NA. These kits are the European spec--smaller bumpers, round headlights, etc. The differences in the bumpers in the kit illustrations are because they are different model years, I assume....the Mk I Golf had an MCE somewhere in it's run...the GTI was added in '76, the Cabrio in '80.
More info here..http://en.wikipedia.org/wiki/Volkswagen_Golf_Mk1