I have a pattern with photos that was at one time posted at thru-hiker by the author (Maurer, 2005). He kindly sent them to me so they are sitting in my inbox. Using the pattern I made a bag that weighs just over 2 lbs. that has gotten me down to zero (with clothes and a bivy). The first step in his bag is to make the hood from the pattern for attaching a hood to a sleeping bag that is still available at thru-hiker.
If you would like me to froward the directions, E-mail me : firstname.lastname@example.org
BTW Ed Speer at hammockcamping.com sells 900 weight down at around $26 for a 3.1 oz. bag. He adds the .1 to cover your spillage!