Possible Clues:

• Old boatbuilder holds tongue at first when sworn in
• Having sworn to be truthful
• Bound to speak the truth, old biblical character about Ararat, ultimately
• Vows having been given to an orderly I didn't know about
• Old ship builder bites tip of tongue, having sworn
• Oddly deficient, down to last husband? Bound to be honest
• Round closing time, Arkwright's not -- we trust -- purveying pork pies!
• You'd swear you could make this to Noah