This is a gap I’ve noticed in my embryonic setting project set in roughly this time period/tech level. Commerce, law, politics, that sort of thing. Probably one skill can safely cover them all, we don’t want to bloat the skill list too much. You could do it with a background, of course, that’s a bit too restrictive for me. You want to be able to create a feckless and incompetent member of the landowning gentry, or a lawyer of humble background who is highly competent, or a trusted servant who handles their master’s business matters. Making it a skill gives more design space.
The other one I’ve been considering is Society. It doesn’t only cover etiquette, but also stuff like understanding who is who, and your ability to do stuff like perform the latest fashionable dances without embarrassing yourself, or know the rumour that’s been going around about the Marquis of Featherington’s younger son. But whether this is required is going to be a matter of emphasis - my project is heavily influenced by Austen, so obviously this sort of thing is front and centre for me.