There is a list of books on the Internet that has been indexed for names, thanks sincerely to Bill Trenwith for this work. (sorry, no contact address available).  See:  http://homepages.rootsweb.com/~mwi/conbook1.txt
I have searched the lists provided on the site above and transcribed a list that may be helpful for Breage/Godolphin researchers- based on Keywords: Breage, Rinsey, Porthleven, Godolphin, Wheal Reeth, Tregonning Hill.                                         Good luck, please let me know if you find any other similar sites/indexes.
The Books that have been indexed are:

[1] THE HISTORY OF THE TOWN AND BOROUGH OF PENZANCE by P.A.S. Poole.         
The Corporation of Penzance. - 1974
[2]  A HISTORY OF CORNWALL by Ian Soulsby. Phillimore & Co. Ltd, Shopwyke Hall, Chichester, Susex  1986                                                         
          ISBN 0 85033 6120
[3]  PENZANCE AND NEWLYN  by Sheila Bird.Phillimore & Co. Ltd, Shopwyke Hall, Chichester, Sussex. -1987                                                         
          ISBN 0 85033 6333
[4]  SMUGGLING IN CORNWALL  by Cyril Noall.   D. Bradford Barton Ltd, Truro. - 1971
[5]  ANNALS OF AN ANCIENT CORNISH TOWN, REDRUTH  byFrank Michell.
Dyllansow Truran, Trewolsta, Trewirgie, Redruth, Cornall.   1985    ISBN 0 907566 85 5                     
[6]  THE MINES OF CORNWALL (The Land's End Peninsular) byThomas Spargo.  D.Bradford Barton Ltd, Frances St, Truro, Cornwall.
[7]  COPPER MINING IN CORNWALL AND DEVON by D.B. Barton.       D.Bradford Barton Ltd, Truro. - 1978
[8]  THE ST IVES MINING DISTRICT (Vol. 1) by Cyril Noall.Dyllansow Truran, Trewolsta, Trewirgie, Redruth, Kernow - 1982 ISBN 0 907566 33 2
[9]  THE BOOK OF CORNISH VILLAGES by Sheila Bird. The Dovecote Press Ltd, Stanbridge, Wimborne, Dorset -1988
          ISBN 0 946159 51 3
[10] ESSAYS IN CORNISH MINING HISTORY (1) by D.B.Barton. D.Bradford Barton Ltd, Frances St, Truro, Cornwall1968
[11] ESSAYS IN CORNISH MINING HISTORY (2) by D.B.Barton D.Bradford Barton Ltd, Frances St, Truro, Cornwall - 1971
[12] THE ST IVES MINING DISTRICT (Vol. 2) by  Cyril Noall. Dyllansow Truran, Redruth, Cornwall - 1993
           ISBN 185 022 0670
[13] LIFE IN CORNWALL (EARLY NINETEENTH CENTURY) by R.M.Barton.  D.Bradford Ltd, Truro.  1970
[14] LIFE IN CORNWALL (END OF NINETEENTH CENTURY) by R.M.Barton.  D.Bradford Ltd, Truro - 1974
[15] AUSTRALIA'S LITTLE CORNWALL by  Oswald Pryor. Rigby Publishers Ltd, Adelaide - 1980
          ISBN 0 85179 218 9
[16] THE CORNISH IN AUSTRALIA by Jim Faull. Australasian Educa Press Pty Ltd, 30 Mt Dandenong Rd, Croydon 3136 - 1983     ISBN 0 86787 200 4
[17] VANISHING CORNWALL by Daphne du Maurier.Penguin Books Australia Ltd, Ringwood, Victoria - 1972
[18] MELINDWR, CARDIGANSHIRE : a study of the Censuses 1841-71 by E. Alwyn Benjamin.
Reprinted from Ceredigion, Journal of the Ceredigion  Antiquarian Society. - 1983
[19] TUDOR CORNWALL by  A.L.Rowse.Dyllansow Truran  Trewolsta, Trewirgie, Redruth, Cornwall ISBN 185022  0581