I think this difference relates to an increase in ride height that was required for Euro 4 compliance. Seem to recall Morgan moved the mounting points on the wishbones/trailing arms??
Clue is in the centre-to-centre dimensions and changes in travel...
No idea what has been done with the Ohlin/ATR options for Euro 3 vs 4 but am aware that many of the later cars were reverted to Euro 3 standard but don't know if this reversion included reverting the ride height.
I don't think there were many EU4 cars built for the UK as using SVA for a EU3 spec car was available. In Europe they would have been EU4 and as you say had raised ride height. For the front it was done with different uprights and at the rear there are two lower mounting points which change the angle of the shock absorber and hence the ride height. As far as I know the shocks were the same dimensions for EU3 and EU4 but in typical MMC fashion they might have been different and they didn't tell anyone
