I recommend Nat's book. His work on the sketches is excellent. I understand that only the Kindle version is available currently, but I hope Nat re-introduces the print version, too.
Paratrooper of Fortune has a lot of new information on Ted. I scanned it and saw it had a lot of original detail from the SOG guys. Al Tyre, who jumped with Ted and is one of the SOG troopers mentioned, is 100% a believer that Ted in DB. Drew Beeson, the author, is 90%.