Possible Clues:

• Think, old-style
• Usually flat-bottomed small boat or barge
• Consider, old-style
• Believe as of old that this ends as 26 across starts
• Believe, old-style
• (Archaic) trust – wort (anag)
• Flat-bottomed barge
• Old-fashioned trust finally went with quarrel
• Think, believe (archaic)
• Suppose, to Shakespeare