well....not all the ke55's had square headlights for starters..(<--- mine is a round headlight)....the later models did, after 1980 i think. the bonnet on the 55 is also different, it has two rises that come to a centre point, and the grilles in the bonnet arent flat, they are more sunken in.
If you have managed to get yourself a aus spec Ke55 then it will prolly have aus spec brakes...(which are bigger on the back).
i think the KE55 4 door weighs around 950 - 1100 kgs. not sure on that.
oh and also they have different rear grilles....near the quarter glass in the back window.