Thank you! I had browsed that site pretty thoroughly, and it rocks. But, I'm still not sure about this book with the "C". I've read that some Edgar Church copies from 1945 and later may have had just a simple "M" or "C" initial without any date code. And, this letter "C" resembles that on some Ohio copies I've looked up. But, you're right --- this sole letter C is not much to go on. No matter, I was really pleased to find this book in a collection I bought recently, and it's got a forever home in my PC now. I'm tempted to submit for grading just to see whether the pros make any note of the pencil mark or not.