My father, LGB illustrator William Dugan, passed away in April at the age of 92. (I was his model for "I'm An Indian Today" :-)). Cleaning out his apartment, I've inherited over 100 mostly-pre-1970 LGB's and am attempting to educate myself as to their value before selling them. (These include a couple of Little Black Sambos and some "A" editions illustrated by Harry McNaught, who was a family friend, and a first edition of The Twelve Dancing Princesses).
If there is no "c d e f...etc" on the copyright page, and no letter on the lower right corner of the final page, is it safe to conclude that a LGB is an "unstated first edition?" If not, how else can one determine the edition of a LGB with no tell-tale letter in the front or back?