The Estes hatchery site has some of the nicest day old chick photos that can help clear a number of the breeds:
http://www.esteshatchery.com/gallery.html
Then go to the Feather site and look at individual breeds.
Ancona: http://www.feathersite.com/Poultry/CGA/Anc/BRKAncona.html
Barnvelder: http://www.feathersite.com/Poultry/CGA/Barnev/BRKBarnev.html
Barnevelder should be a darker chipmunk than the Speckled Sussex, SS should have beige/pink legs (should although hatchery quality can vary) and the Barnevelder appears to have more dark yellow
Speckled Sussex: http://www.feathersite.com/Poultry/CGP/Sussex/BRKSussex.html
The hatchery should have some pics as well.
I do think you'll be able to tell them apart mostly....hopefully they used Ameraucanas in the Olive Egger combination so the beard/muff will be a dead give-away if they come out looking chipmunky or dark.
If you can't figure it out, definitely post a new thread here, and likely somebody can help.
Lady of McCamley
X2