http://www7b.biglobe.ne.jp/~bprince/hr/foxdavies/fdguide03.htm
There are a couple of useful images and the best is certainly this. It is listed as being from later in the 15th C but shows other images of version of crests that we see in art from our focus period. So much choice! I would love to see something like this at an SCA event one day. Maybe not 4 shelves. Maybe not 3 whole walls, but a display near the lists for a tourney.