Moto zip up Jacket

This is a beautiful corduroy jacket. It says it's a large, but it's actually a small medium. The dress form is actually a size small and I think it would be a little tight for a medium.

I'm going to label this jacket us a size med. For the American market.

 Here are the jacket specs. 

 The body length is measured from the neck all the way down to the bottom hem.
 21 1/2 measured from the neck to the center front
20 inches from neck to side seam hem.
 19" from neck to center back hem

 This is an asymmetrical hemline. It's a longer at the front and shorter at the back.

The shoulder width is 17 inches
Neck width is 11 inches
cb collar height is 4"
The sleeve length is 23 1/4  from Shoulder seam to slv opening. It's a little short, but I think it's considered a bracelet length. 
Bicep  13 1/2 inches
 Sleeve opening is 10 inches, and in the middle under sleeve is a ribknit for mobility and comfort

 Chest is 41"  that's 1 inch below your underarm.
38" hem circ.