The buildings are hardly touched structurally as they are Historical monuments.
The surrounding out buildings and service areas probably need removing from modern pics but the buildings are as they were then apart from the colour, mostly black / grey stone work due to dust / soot etc.
Roofing materials and structures should be the same as they restore the lead copper like for like to preserve original specification, see national heritage and English heritage web sites, so there should be no structural changes made.
As for Dover pier this site might help.
http://www.subbrit.org.uk/sb-sites/s...er/index.shtml