Possible Clues:

• Perplex old Black Panther, say, in what melting pot will do?
• Hide significant details of case, but getting sorted out
• Obscure cafe — but so original
• Be at focus? Not exactly what Sir Humphrey does
• Be a fine scout, tricky to confuse
• Dim alumnus wore subfusc?
• Muddle
• Darken — bewilder
• Confuse most of our facts — be confused
• Bewilder old boy, and reportedly worry girl