Philalethes, I am 150lbs and 5.9", exactly your size. My first HWM was a regular 38" size. It was too large for me. So, I sold it and I tried to find the perfect measures for me. Like many others on that forum , I want a slim fit even if the jacket was not designed that way.
Amanda is so sweet and helpful, but she always follow the idea of their pattern according to 30s-50s and that means a boxier cut with lower armholes.All you have to do is to take the risk and ask the measures that you think will work for you. I risked and ordered the next HWM one size smaller ( 36") and with some cut changes . I can tell you that it works . Now I have a HWM almost perfect. Why almost? because is very hard to make the HWM a slim fit jacket. Maybe the third HWM will be perfect . You should also need to know that it is impossible to cut the jacket exactly according to your measurements. There is always a margin of error because of thickness of the hide and because of pattern that can be changed only within certain limits.
But but I learned a few rules and maybe will help you ( for slim fit ):
* the jacket armpit should be 2"-2.5" over your body armpit if you want heavy steerhide .
* shoulder jacket 1" less than your body shoulder.
* the jacket bottom measures is also very important
* the neck opening could be a little to small if you downsize. If I wear a neck sweater I can't take the zipper up top. ( I ask 38" neck opening, but I don't know what happened... )
* the collar is a little small on 36". I also ask the 38" collar but ...
However, if you are very picky, like me, get ready as the first coat to be not quite as you expect .
Radu
Amanda is so sweet and helpful, but she always follow the idea of their pattern according to 30s-50s and that means a boxier cut with lower armholes.All you have to do is to take the risk and ask the measures that you think will work for you. I risked and ordered the next HWM one size smaller ( 36") and with some cut changes . I can tell you that it works . Now I have a HWM almost perfect. Why almost? because is very hard to make the HWM a slim fit jacket. Maybe the third HWM will be perfect . You should also need to know that it is impossible to cut the jacket exactly according to your measurements. There is always a margin of error because of thickness of the hide and because of pattern that can be changed only within certain limits.
But but I learned a few rules and maybe will help you ( for slim fit ):
* the jacket armpit should be 2"-2.5" over your body armpit if you want heavy steerhide .
* shoulder jacket 1" less than your body shoulder.
* the jacket bottom measures is also very important
* the neck opening could be a little to small if you downsize. If I wear a neck sweater I can't take the zipper up top. ( I ask 38" neck opening, but I don't know what happened... )
* the collar is a little small on 36". I also ask the 38" collar but ...
However, if you are very picky, like me, get ready as the first coat to be not quite as you expect .
Radu