Here are all of the links to the various things that I looked into over the course of the series. Things that popped up in an episode and I wanted to find more information about them. For each entry the episode number of the first popping-up is in parentheses.
Thanks, AJK for putting these links all in one place. Even though I didn't finish watching this I did go and check out the links, just like when I was watching Jang Youngshil the links with "extra" information can add to the story and like in Jang Youngshil make you really appreciate what he invented, and the craftmanship in that day and age.