54R euro (42R US sizing). Your chance to try the Kiton soft shoulder styling at a very reasonable price. Much too small for me today.
Actual buttonholes. 10 in from center to arm seam. 23.75 in from arm seam to end of sleeve. I wear 16 x 34 shirts. Chest is 42 in around. Waist is 39 inch around. Length from top of collar is 32.
Please note that my entire jacket and suit collection is for sale given my retirement to Socal beach area. Most are 44L or 46L. Some are 44R or 46R. Brands are Brioni, Zegna, Oxford, Canali, Brooks Brothers and others. I will likely keep most of my Kiton, but this garment simply was the first Kiton I bought and it no longer fits me.
Note: there is a small tear near the front middle buttonhole shown in a couple of the pictures. I will leave it to you to have that repaired if you like.
Be well and thank you for your interest.