Boston, MA. 05/ 15 /09: On controversy over the planned demolition of the Isabella Stewart Gardner Museum's Carriage House to make way for a major expansion/renovation. Sources inside the museum are coming forward with new research suggesting that the Carriage House is much more historically significant than the museum's management has admitted. Internal dissent has been suppressed, and for these opponents, time is running out before a board of trustees vote on Monday. ( David L Ryan / Globe Staff ) section: ARTS slug: 17gardner reporter Sebastian Smee 07gardner 21gardner