Captain-whose-name-I-Am-Forgetting-Right-Now mentions "Gun" Shellfish, and how they were named after guns who would misfire. So while firearms haven't reached the region yet, they very much exist and are in use elsewhere.
Isn't "Lushia" meant to be "Rushia"? From the way they describe it, it´s "Even further north-east than the northern provinces", "on the edge of civilization. It's an incredibly cold place" it sounds like it's meant to be analog Russia.