Just ran across this on coinweek and though others may be interested. Some interesting ideas on grading towards the end: http://www.coinweek.com/coin-guide/numismatic-history/walter-breen-interview-from-1986/
I liked his work, (a little cavalier sometimes, but still), and the fact he was a true pioneer in many US fields. The whole information that came out later was disconcerting, to say the least, but still a great numismatist. Chris