Thanks for the replies. Let me try to answer a few questions. I have a fair amount of experience with my first M90 Kinsmans so as far as temps go I put it good to about freezing for just standing around. I have used the stock kinsman on a number of trips where I paired it with a Minima vest (3.0 oz primaloft) and found it worked down into the teens with snow and raining conditions. A light merino LS top + vest + pullover + WPB shell worked well in almost any condition I would likely be in.
As far as the process for adjusting the pattern goes I started by basically reproducing the existing pattern by tracing it onto a roll of giant graph paper (purchased at a teaching supply store). I then adjust the lines free handing it. The straight lines are easy. So for the collar all I did was move the base line up 1/2". The sleeves were pretty easy. I just moved the long lines in 1" each at the top of the sleeve and 1/2" at the bottom (wrist). The curved lines are more difficult. The hardest part was adjusting the side curves of the front and back so that the arm girth was now smaller. When the body arm girth shrinks this impacts the sides as well. I started by using a piece of string to measure the length of the arm girth at the sleeve. Next I used the string to determine the length the girth needed to be for the front and back body peices. Then I free handed a new set of side curves so the sides now met correctly. I accounted for all seam allowances and basically confirmed the length of all matching curved lines with a piece of string.
I didn't do any prototyping. I went right from the adjusted pattern to making the down pullover. It turned out perfect. Everything matched as well as the stock kinsmans. I think it was a little luck and lot of just triple checking the length of each line that needed to match. I really have to credit Ayce at thru-hinker for making a great pattern to start with.
I too hope to see more of us sharing MYOG projects. Seems like we have slowed down a lot. With the price of M50 being so good now and the multiple colors thru-hiker offers I think there is a lot of opportunity to make some fantastic items.
Jamie