Lewis,
I know the car you are talking about. There we actually at least three Alloy bodied ACMkIII's in Duttons in the 90's. On BRG with classic leather, one red and one dark blue (either off white or Silver stripe). There was also an FIA. They were there around the time of the Dutton sponsored GP Rallye, and had his custom porsche he made for Targa (1992 I think).
After all that, can't tell you where they are today
You could try contacting them directly, Geoff has always been helpful with enquiries from enthusiasts.
Regards
Cameron