I just finished my M50 900fp down pullover jacket. It was based off a modified Thru-Hiker Kinsman pattern. I had to make some adjustments to account for down instead of synthetic insultion, but that was easier than I anticipated. The final weight on the jacket is 5.1 oz. I used 2.25 oz of down.
My thanks goes to Brendan Swihart. His M50 jacket inspired to make this one. He helped with some crucial sizing decisions. Things I modified from the Kinsman were: reduce collar height by 1/2", reduce arm girth by 2", and shorten the front zipper by 2". All in all it is a simple jacket...no pockets, no waist elastic, etc. I did add elastic to the wrists (Brendan did not).
Here are some pics.