Grabbed this beautiful bag from a "vintage" shop in Brooklyn:slayer: (of course). I don't think the guy knew what he was selling... Anyway, it's definitely a vintage Field Satchel but I was wondering is there anyway to determine the age of the bag? I'll save my questions about what I should do to preserve/repair the very minor issues with it. It's an awesome bag, I just would like to know when it was made. The store said the 30's but I really don't know if that's...