And you didn’t mention it here, but the guys in that game were a little thrown by referencing the size of the area they were in as being twice the size of “New Jersey”. Even to me it sounded like an odd comparison. Maybe compare things that folks on both sides of the pond could understand easily enough, like comparing to the island of Great Britain or some other modern European country. I think even Americans (especially those interested in this game) will be able to understand a Euro-centric reference easily enough.
As was mentioned about the costs, if that’s written in the scenario about Marks but all of the characters are carrying Gulden, then you may need to make sure a table for exchange rates would be handy. And while it gives a sense of having different monies to deal with I’m not sure it’s something most players are really going to want to deal with that often. It might get in the way of the role-play if it’s too cumbersome or comes up too often.
Beyond that you need to check out some of the RPG groups on Twitch, maybe even get one of them to run either a single-session game or maybe even a multi-show mini-campaign. Not sure the best way to try to do that, though. Still, having it recorded is pretty cool and made me think of getting one of the well-known groups to run something like this. A group like that might even help out with setting up some Codex specific stuff for Roll20. So thanks for sharing, Jack!