Or better yet bring him an actual garment. A good tailor won't even need to take it apart. The hardest thing is to articulate a silhouette verbally.
I thrifted a vintage E. Tautz and Sons bespoke suit that was made for an American. The shoulders are very natural and beautiful and American but the quarters are very closed and English. So the natural shoulder can be made well anywhere.
^ I did this with George of Haringey with good results.