As far as i understand the slim fit shirts are different. I mean, for example, John Francomb shirts are more fitted than Buckingham Button Cuff slim-fitted shirts.
I'm a very typical size medium, wearing a 16" Collar, 40" Suit, 32" Trouser, but I have trouble getting any of your shirts to fit me in a nice tailored fit as the 16 is massive even in the slim-fit st