I've got the full Red Book listed set. Now I have to try and ID the die varieties. My set consists of 33 coins only 4 of which have been identified. I tried once before and found that it's NOT a trivial exercise. I've got the definitive book, The Die Varieties of United States Large Cents 1840-1857 by John R. Grellman, Jr. The most widely used identifying system is Newcomb Numbers. I also have a reprint of the original Newcomb book. The Grellman book has eliminated many of the varieties listed in the Newcomb book. Grellman found that Newcomb had identified many coins as a die variety that were in fact a die state. This time I'll try to be more patient but many of the identifying features are just slightly different from one coin to the next. And other identifying features are lost rather quickly when a coin has been circulated. If the going gets rough I'll have to see if I can get help from others in here. And maybe from EAC too if they deal with this issue.