There’s very little info on these models available so from what I can see the Mk1 had some appearance differences throughout its life.
There seems to be some slight differences in body styles as well with some models being roadsters, others T-Tops and some Coupés. Roadsters may have been special orders though and the Coupé and T-Top appear to be the same but the T-Top just has a larger piece of glass on the door.
The prototypes and the first batch of production models produced until somewhere around 1995 looked like this:
Around 1996 it was given some proper fenders and had the appearance updated, these models were produced until 1997/1998.
Some sources claim until 2002 but from what I can see only the Race Models were used from 1998-2002 where production for road models then progressed onto the Streiff.
If anyone has some concrete information (that can be confirmed with reliable sources) then please feel free to ping me and I’ll update this topic.