Have ever gone to other sights? uk-genealogy.org.uk/england/Cornwall/visitations/index.html
findagrave.com familysearch.org All of these are free. A book by Stanley Vivian called The Story of The Vivians ISBN 0 9514814 0 1 you can order one from Anne Dhanani 37 Lynwood Rd., Ealing, London W5 1 JQ UK I got my copy in 2002
The book does have some information on some Vivians that went to Australia on pages 120-131. Other references: 1. The Cornish Miner in Australia 1984 by P. J. Payton, 2. The Cornish in Australia, 1983, by Faull. I hope this will help.