Ok, you've got the armour and the 3 maps, you need the 4th out of the prison cell in the SW Dwarven Halls, requiring Lockpick level 5 to open it. And as you're already in the Dwarven Halls, pay Strobur a visit. Why? He's missing his brother Rimmer from the Dwarven village Glenborus in the East Rivertown area and wants you to send his greetings. If you do this, you get 5 bottles of Rimmer ale for free. Keep this in mind: The Larians are Belgians, and Belgians like to drink beer.