I can tell you a couple of things, AFAIK mirrors cannot extend more than 200mm beyond the width of the car, or trailer if towing but must extend beyond the width of the widest part of car/trailer.
Height is unrestricted
The offside mirror I was told should always be plain glass, not convex, but I know on LR this is not the case so I don't think it can be the law.
"Objects in the rear view mirror may appear closer than they are" no,it's just Meatloaf ate all the pies and appears BIGGER than anyone else :lol: convex mirrors give a wider field of vision at the expense of true perception of distance, ie things appear further away and approach faster.
I also think they can be tinted slightly and it's still not a legal requirement to have a nearside mirror if you fit a centre mirror.