Byron,
My wife is a book collecting nut and she informed me that the book you have that is marked, "First Printing", is worth more than the one with only the copyright date on it. How much more she cannot say. It is worth more because that is the first printing and if there is more printed, they would not be worth as much as the First Printing. I guess it would be like the "First Printing" is the original and all that follow would be copies. As to how many were made and marked first printing is an unknown and only the publisher would be able to answer that.
Warren
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.