I actually think the Aristocrat might be a great idea for a calling that PCs or NPCs could use! I think you're right that that character is currently not super well-represented in either book, but I definitely have players who would want to play it if it was an option. You could maybe steal Honor Challenge from the Champion in MoM? Add a secret or trick related to having wealth and using that to acquire items, similar effect to Crafter but with a different theme of how you got there?

I might add a Secret/Trick to the Expert which I think would work great for like, truly expert librarian/sage...