A 1990 registered 2WD would have ambers, and be identical to an '89 2WD.
The '1990 facelift' included all the 4x4 changes. There is no overlap with smoked lights being used on 2WD cars etc.
There is defiantly another revision, pre the 90 one you mention, which had different fuel cap, 'hooded' dash etc.
The changes includes the instrument cluster, different speakers (mine are square, prior to this they were round) and two of them were removed, as well as other things, mine has the number plate surround and the lights are marked security marked, so I believe it to be original.
Martin