Here's a few interesting ones- especially the Lucas. I think they are nearly 10" dia.

http://cgi.ebay.com/ebaymotors/1940-...Q5fAccessories

http://cgi.ebay.com/ebaymotors/Vinta...Q5fAccessories

http://cgi.ebay.com/ebaymotors/1930-...Q5fAccessories

http://cgi.ebay.com/VINTAGE-HEAD-LIG...item439d585279

http://cgi.ebay.com/ebaymotors/1920s...Q5fAccessories

http://cgi.ebay.com/Vintage-LUCAS-M1...item35a7309236

http://cgi.ebay.com/Vintage-LUCAS-M1...item35a730d1b1

http://cgi.ebay.com/Vintage-LUCAS-L1...item35a730f60f

http://cgi.ebay.com/Vintage-LUCAS-S7...item35a73114a1

http://cgi.ebay.com/ebaymotors/1920-...Q5fAccessories

http://cgi.ebay.com/ebaymotors/Nice-...Q5fAccessories