Possible Clues:

• Case that used to be more than big enough?
• English vote more than enough, for instance
• A model for a girlfriend? Once, that's enough!
• For instance, a former partner has plenty
• Test learner in gym class, for instance
• Model and former politician drowning in beer
• Model or illustration
• Having large volume at foot of second book case
• From plenty, taking one instance
• Specimen test - appeal if not getting top grade