The to do list looked something like this..
1. Move princess line seams towards the armhole.
2. Add new seam for the off center zipper.
3. Cut out slanted yokes on front and back.
4. Cut jacket body so there is a sewn on belt like bottom
5. Redraft collar so it is a 2 piece with collar stand.
6. Do normal fitting alterations - forward shoulder, wide upper back, narrow lower back and decrease sleeve cap ease.
I made the changes for the princess line seams and the zipper and made up a second muslin to see if my pattern drafting instincts were correct. No pic of that, but the changes seemed to be on track. So then I carried on making the rest of the pattern changes and decided to mock up muslin #3 in some cheap pleather that was in the stash. That way I could get a little experience with sewing right the first time and see how the jacket looked in a fabric closer to leather.
It seems like I'm in the general ballpark now but there are still some ease issues to take care of. It seems that there is too much ease in the upper back now and maybe too much still in the lower back. I don't want to make the jacket too tight to wear over a few layers but I want it too big either. So back to pattern drafting for me. Drat.