Sorry, only just saw this. Yes, entirely original.
It was the Z1100 A3 (if memory serves) the shaft drive version. You'll recall the Z550 and Z750 which were very popular, this was the 1100 version. There weren't many around (I bought it new) even after it was launched. A big cruiser and lots of fun. Being a tall chap, I wanted a 'big' bike in physical size.