Vintage plus size designer coat dress

This blue coat dress was designed by Sandra Ow-Wing for N.R.1. This was one of the early designers of plus size business attire. Dress is executed in blue twill with 3/4 cuffed sleeves, back vent for ease, dropped sleeve construction. Vintage size 14, torso approx 44-46". Buttons have become a little tarnished over time due to loss of finish. One shoulder button apparently fell off and was repinned on. Slight staining at top front left, this I expect should come out.