I am sorry that my earlier post has not been fully reproduced. The  following 
theses on the early history of  Virginia can be found on the  on-line Index 
to UK theses.
 
J.A.Bush, Early British immigrants to Virginia 1615-1635 (Oxford University  
B.Litt. thesis 1977)
 
S.E.Hillier, The trade of the Virginia Colony 1606-1660 (Liverpool  
University Ph.D. thesis  1971-72)
 
T.D.Knight, The social construction of gentility in Virginia 1607-1776  
(Oxford University D.Phil. thesis 2004)
 
J.R.Pagan, Trade and politics in Virginia 1625-1660 (Oxford University  
B.Litt. thesis 1974-75)
 
M.H.Williamson, Examination and re-analysis of the early sources relating  to 
the Powhatan Confederacy of Tidewater, Virginia in the seventeenth century  
(Oxford University B.Litt. thesis 1972-73)
 
It should be possible to order a microfilm copy of Dr Knight's thesis  
through the British Library's on-line ordering service.
                                                                     
Christopher Thompson