This is an interesting design I came across. It looks like something that could be easily duplicated at home by a skilled fabricator.
http://www.restorationramps.co.uk/phdi/p1.nsf/supppages/ramps?opendocument&part=2
http://www.restorationramps.co.uk/phdi/p1.nsf/supppages/ramps?opendocument&part=2

joke btw