I have been wanting a Schott 618 for years and am finally getting around to getting one. The website says to size up. I intend to wear it casually as well as when I ride. My wife measured me at a 41" chest and I currently wear an Alpinestars 42" jacket or 42" Dainese suit. This size is comfortable for me. Would getting the 618 in a 42" be the right size or do I need to size up further? (Not sure of any variances there might be in manufacture) Thanks in advance.