As time goes on, more and more publications are digitised and become freely (and legitimately) available online. Not finding any threads dedicated to listing such resources, perhaps we should have one.
Here is one book of interest, courtesy of the Smithsonian:
American and European Swords in the Historical Collections of the United States National Museum
Belote, Theodore T.
URI:
http://hdl.handle.net/10088/10007
Date: 1932