They are non-functional, but they have the detail Asian Afro described. I'll take a photo shortly and post it up. As a side note, the coat is fine for the current weather if you are a generally hardy guy. I wore it on Thursday and the people I met for lunch asked me if I thought it was spring already.
Based on my experience with the grey twill, I would go by the shoulder measurement (which led me to a 54). The chest will be plenty trim, regardless of the measurement. If you look back at my pics of it, I'm a 19" shoulder 44" chest and the 54 is not roomy.
The neck band height is 1.5" (3.75 cm).The front neck band height is 1" (2.5 cm).The collar back height is 2" (5 cm).The collar point length is 3.25" (8.25 cm). This is the same as my recent vintage BB OCBDs.