The fact that I keep wanting to read this as Codex UNO not withstanding :-) this is a collection of fun items/artifacts that likely won't break the game. What's more, there's plenty of backstory to each of them. You could reasonably build a mission around retrieving them or dealing with the fallout of finding one, e.g., being hired to take the Katana MK IV off of Daiki Masuda or finding the katana and Daiki thinking you stole it.
Minor issue: Some of the images line up with their descriptions, while others roll over to pages of different items.
Lingering question: What was that nun doing wandering around a monastery in 1870 toting a revolver?