Currently the crew under my captain provisionally has an officer to lead the boarding party, a gunner, a mechanic/engineer, gun hand, crew lady. I don't think I've missed anyone who has spoken to me specifically about joining the Comet. If I have please correct me.
I think a flier who may or may not be a spy for the ship as well. A tinker, armourer or inventor to keep these pesky rockets working properly, a doctor of some kind and a cook would be valuable additions if people are looking for potential role to fill. That doesn't mean that suggestions won't be taken. These are just obvious gaps in the crew from the captain's perspective.