My Burda 7576 jacket muslin

We were supposed to have our jacket muslins ready to go for Sherry's RTW Jacket Sewalong from the start of April, but like a few others I have been running late with it.  I got my pattern and fabric in time, but have only just finished the muslin - more than a week late!

Here's what it was looking like on the dressmaker's dummy last night - I was comfortable with this:

 

but today I got my partner to take some pictures of it on me - oh dear! Clearly the dummy is a better clothes horse than I (and probably not the same size as me either lol)!  Too loose in front, too tight in the back, arm set-in not right....

 







I made my muslin in a size 12 in the shoulders, arms and bust, grading out to a 16 in the waist and hips. I'm thinking to I'll adjust it to a size 18 waist and hips for the real jacket.  I don't know what else I need to fix, can you see what else I need to do? I know I set the sleeves in badly but I'm hoping that was just due to fatigue (late last night)...

The other thing is that I was planning to make this up in a warm wool, in a nice olive green sort of colour.  However, this little jacket seems to be intended to be made in light suiting or linen, and I don't think I have the skills to calculate the appropriate turn of the cloth and to add the right amounts of ease for a thicker fabric. So I may end up making it in one a red linen or a wide red/cream striped light-medium weight upholstery fabric. If I go with one of these lighter fabrics I can always have a go with the wool later, can't I - or should I push myself to the limit while Sherry and others in the Sewalong are available to help?