I am 6'2" and 180lb with wide shoulders, i easily fit in jackets with 18" shoulders. If you like that jacket get it, it will most likely be ok.
It's in the classifieds right here: https://www.thefedoralounge.com/threads/fine-creek-leather-hh-james-size-40.102448/
My concern wasn't the shoulder width, it was the p2p. Fine Creek runs small and a 20-inch p2p would be tight for a size 38 and about right for a size 36. You normally want 3-4 extra inches around the chest. You say you're 5'8, 175. Unless you have tree trunk legs and a very thin upper body, I find it hard to believe that a jacket with a 20-inch p2p would fit you.
I told the seller I was going to pass due to fit concerns and he said with his 18” shoulder it’s snug on him. I guess it’s why he’s selling. Too bad. It looks to be a nice jacket.
My rule is if its looks to be a gamble on size then it has to be at a low enough price that I know I can pass it along without too much loss. Sounds like the right call on this one.
I like that rule. Its why I started this thread. I just don’t know how much I could get for this jacket if it didn’t fit. I don’t have enough experience. When I sell my Maxwell I think I can get about what I paid for it so feel good about that. I have no idea with this jacket.
Actually a great price for this jacket. You could prob sell it on Grailed for way more with better photos.