I have made several jackets, not this one, but I would make the lining as one piece and the outside as one piece and then sew them from the front all the way around. Leave an opening at the middle back bottom so you can turn it.
Let the sleeve ends open until you turn everything. Then fit it to you, maybe the sleeves are too long, and after finding out it fits, finish the sleeves. I would put shoulder pads in for myself, maybe you want to, but secure the shoulders together. If you want to, topstitch the lining down all the way around. Good luck.