Bruce - I am not sure if you are still involved in the Rosevear history, however I would like to add some more information for you.
Mygreat grandfather John Pearce married William's daughter Jenefer on 27 April 1865 in Tasmania.They had 7 children, and my grandfather Edgar Louis was born in 1877.My late father Louis was born in 1910, while I was born in 1940.In 1983 the 150th reunion of the arrival to Australia of the first Pearce in our family James was held and a book along withthe family tree at that time was published.
There is a great deal of information in the book about John and Jenefer, and I also have a photo of the gravestone shared by both John and Jenefer.
In 2009 Maggie and I travelled to Cornwall to try and trace James - without much luck and stayed in St Ives for 3 weeks.However by sheer coincidence we have also stayed at Port Isaac during a previous trip and drove through Camelford where William came from!
If you wish to obtain any more information please let me know and I will add a little more to the fascinating tale of the Rosevears in Australia!