Possible Clues:

• Small, four-stringed guitar
• With Britain, you get it with twice the French
• Musical instrument once played by George Formby
• One needs pluck in this country's university, and double the French
• Attending British university, the French take up the Spanish guitar
• You, between Great Britain and the two in France, could be in Hawaii with it
• George Formby's little guitar
• Arthur Godfrey played it
• Luau performance aid
• Its common tuning is known as 'My dog has fleas'