Former NBS President Michael J. Sullivan writes:

"Your mention of the Cogan letter in the Library of Congress provided just the first paragraph of a lengthy letter by Cogan on the Randall Collection cataloguing debate between himself and "Brother" Mason. Mr. Charlie Davis has done the numismatic community quite a favor by reprinting all known Cogan letters on this topic in his three volume reprint of a complete set of Mason periodicals. The letters appear as a supplement in the third volume. By reading the Mason periodicals and the Cogan letters, one can see how the initial rankling turned into a lambasting debate. Copies of the book are available from Charlie Davis. Besides, the reprint at around $160 is only about 2% the cost of originals if you can ever find them."