Woah, what an interesting site! I'm a very amateur currency (mostly paper money) collector and have struggled mightily with creating a searchable collection index due to the differences in how various countries mark their currencies. I don't have anything particularly old, but have a bit over 1,000 individual pieces.<p>From time to time I need to rely on hours of searches all over the web to try to identify a particular piece or variation of a piece. It can sometimes just be too hard. These kinds of passion sites are what made the old internet incredibly valuable and I'm so glad they can still exist.<p>The text here about American paper currency is also really interesting <a href="https://creounity.com/apps/time_machine/?go=mints.php&lang=en" rel="nofollow">https://creounity.com/apps/time_machine/?go=mints.php&lang=e...</a>