I don't know anything about the copyright situation on Sanborn Fire Insurance
maps, but I can tell you how to get printed copies. Order the following
through interlibrary loan or direct from the publisher:
 
Sanborn Fire Insurance Maps, [Microfilm] Chadwyck-Healey, Teaneck, NJ, 1983.
 
This is a 35mm microfilm collection consisting of 58 reels beginning in 1868
and ending 1950. The microfilm collection was reproduced from original copies
in the Geography and Map Division of the Library of Congress. Each reel is
indexed by city. Maps are arranged in the order that they appear in Fire
insurance maps in the Library of Congress, 1981.
 
You may be able to order the collection or a portion of the collection based
on the state that you are in directly from Chadwyck-Healey.
 
Regards,
 
Pat Tucker
Lab of Archaeology
The University of Toledo
Toledo, Ohio