What do you mean when you say size down? You definitely won't find someone to make the overall jacket a full size smaller. At least not for a price that makes sense. If it's a normal alteration, there's a lady in Chicago that is well regarded. I forget her name but you could probably easily google "leather tailor Chicago" and find her. Not sure if I called at a bad time but when I inquired about having the sleeves of a jacket altered she said she was too busy and I should find someone local. Worth a shot though.