A detective probably isn't too far fetched. We have several already. [Note that Armin fails to understand, or at least remark upon, the gentleman distinction.] But... if that's what you're going with, you probably want to try to moderate your perspective - and your skills, your apparent experience - to match the cover. At least a little. There are reasons I assumed you were a spy, and not a detective.

...Perhaps an undercover detective? Though I'm not sure if that's a little too close to the truth for comfort. [Armin gives something of a shrug.] It's true that there's probably not much you could say that would strain the credulity of this group too badly - but I'm afraid I'm not really familiar enough to know what other options there might be for a person with your skills. There wasn't really a need for them, in my world.