I am not sure this page is still being updated:
http://www.caramel-cards.com/e104.html ? I was looking on there for E104 checklists and noticed that the E104 Collins is not shown with Nadja back. I then looked at Old Cardboard, and their checklist shows no E104 Collins with Nadja back. If anyone is interested, E104 Collins is confirmed with Nadja back. I'm sure most of the E104 guys knew this, but if you are new to the set, like me, it is hard to find a real current checklist of known cards. Anyway, just sharing. Happy collecting.