Possible Clues:

• Lozenge
• Letter to doctor - it has four sides
• Figure it's the right house doctor needed
• That's like a diamond
• Lozenge resulting from foreigner's letter to doctor
• Diamond rings - his old man's business, originally
• Lozenge resulting from letter to a Greek doctor
• Letter from Greek graduate - it has four sides
• Figure at right hand of first physician
• Lozenge produced by doctor meeting character in Greece