I'm not that unusual. In the model railroad hobby, folks like me are often labelled as "rivet counters", likely to point out how a new plastic locomotive has only seven rivets below the window when the prototype of course had eight.
Of course, model railroaders aren't the only obsessive, borderline OCD folks out there. And here'a great example: Adam Savage, host of Mythbusters, is not only a Hollywood special effects model maker, but also enjoys reproducing famous props from movies. He's a particular fan of Blade Runner, and not only made a reproduction of Harrison Ford's pistol in the movie, but also videotaped himself making a carrying box that would have been perfect in the movie. (Watch that movie too - Adam shows some techniques that might be handy for model railroad construction, too!)
Adam got his own chance to be a rivet counter when he got to see the actual Blade Runner pistol. Watching him explore the actual prop and find where his model was right and wrong makes me think he's quite a kindred spirit. Too bad he's not that passionate about canneries.