The 16th Jul 1809 baptism gives a birthdate of 13th May 1809, so that doesn't help. William BURT married Sarah BERRY in 1824 at St. George's Church, East Stonehouse. They baptised William Henry BURT at Plymouth Charles in 1827. Sarah BERRY was buried at Plymouth St Andrew in 1832. In 1851 William is living in Stoke Damerel, but declares his age as 50 b. PLymouth.
Also in 1851, there is a William BURT aged 41 born Devonport, whom I believe to be the William baptised 1809 at Stoke Damerel. The 1809 William married Elizabeth BARRY of Launceston in St Germans on 29 Jan 1835. They had at least 6 children between 1835 and 1851.