Pattern Modification

This is for the Simplicity 2313 jacket pattern that I want to make from the faux snake skin. The one that did not fit when I constructed the muslin. I modified the sections of the pattern that I needed to make bigger, and tried to modify sections that would not interfere with the construction in pocket placement, etc.

I made the sleeve larger

And I enlarged the arm hole sections by trimming. Will it match? Who knows.

I added  width to the side front behind the pocket placement. I really don't know if this will work in theory...

Then I added width to the front

So the question is, do I make another muslin? Or do I hope that my mad (not) math skills are adequate and that all will turn out well?

The muslin fit from the first run, before I modified the pattern can be seen here.

Muslin for Simplicity 2313

I'm really glad I decided to make the muslin for this jacket before cutting the faux snake skin that I'd like to make it out of....
because it doesn't fit

It is very close, just a little tight through the upper arm and the waist. Guess I'm up for some reading because I have no idea how to alter this. There are four front pieces, and three back pieces all of which attach to either the pockets or the sleeves, except the center back, and that fits fine. Maybe I should just enlarge the sleeves and the center front pieces at the closure...I have no clue.