Galazan's have an extensive range of trade labels, but probably not C.W. Andrews, since they seemingly made very few guns. I have only ever seen one - 450/400 NE double rifle. AFAIK, Boothroyd does not mention Andrews in any of his books,

In Nigel Brown's book "London Gunmakers", the following addresses and periods of residence are given;

CW ANDREWS, 6 Winchester Street,EC, 1882-93
CW ANDREWS LTD, s.a. 1894-91; 5 and 6 Great Winchester Street, EC, 1901-13; 2 Bradford Ave., 1913-17