Davenport Companies, the new owner of the old Registry of Motor Vehicles offices at 165 Liberty St., is marketing the site for commercial redevelopment, having bought it from the state in June. "We have received a surprising number of offers," said Charles Irving, principal of Boston-based Davenport. "All are retail/restaurant uses. Some want to tear it down. Some want to reuse the existing building. We are looking at it from all angles right now."