Possible Clues:

• Extra
• Villain discovered island in middle of Portland is spare
• -- member system, a method of proportional representation
• Getting on top of things more?
• Extra diamonds in mine entrance by island lake
• Supplementary to what is already available
• More Italian, odd after translation
• … as well as a bit of maths with a student
• Not full member
• Extra lad, an idiot to be licked into shape