Possible Clues:

• Spanish noble's greeting: 'Happy returns with love'
• Spanish gentleman concealed name from old union
• Nobleman says: 'Hello! Happy to turn up with a ring'
• Spanish gent concealed poor Olga
• House in which, delighted, one is put up by foreign gentleman
• Mexican state
• Concealed a concealed goal for Spain
• Spanish noble masked in the past, nicking money
• Foreign gentleman's house (happy one to be raised in)
• Spanish gentleman stowed away a litre before journey