Advice sought for display of images on museum website

At the risk of going over old ground (I am new to the list) I am hoping that some of you might have some advice for us. We are a museum that will soon be launching a public online collections searching application with which users can retrieve information about and images of items in our collection. Our collections are strongly weighted toward modern/contemporary.  

The first question is, to what extent would the use of copyrighted images in this context be regarded as "fair use"?  

Assuming the museum decided to play it safe and not claim fair use, what would we do in the following hypothetical cases? (which are considered "published" for copyright purposes, what copyright terms apply, are the works in the public domain, what is the risk of publishing images of these on the museum's website, etc.?)  

1. A painting dated 1915, painted in the United States, purchased by the museum directly from the artist in the same year. The artist's death date is 1941.
2. The same painting, purchased by the museum out of an exhibition at the museum in 1918, in which all the works on display are for sale.
3. Same as 2, but the artist was French and the painting was painted in France.
4. A painting dated 1933, painted in US by a US artist (death date 1955), with no copyright notice on the work itself. The work is displayed at a commercial gallery in 1934 but is not purchased. It is eventually purchased by the museum from a commercial gallery in 1950. There are no records in the US copyright office related to the work.
5. Same as 4, but the painting has also been reproduced in an art magazine, with copyright notice, in 1949.
6. The museum commissions a work from a US artist in 1935 and the work is immediately accessioned into the collection. There is no language in the paperwork related to the commission specifying anything about copyright. The artist's death date is 1965.
7. A US artist, death date 1965, paints a portrait of a friend in 1930, and gives the painting to the friend, who in turn bequeaths the painting to the museum in 1970. There is no explicit copyright language in the bequest and no paperwork associated with the initial gift of the artist to the friend.
8. A US artist, death date 1941, paints a painting in 1895. The painting remains with the artist until his death. The artist leaves the painting to his son. The son retains the painting until his death in 1961. The son's estate holds a public sale and the museum purchases the work (no copyright notice on the work itself) in 1961.
9. An African artist (name unknown) carves a comb out of ivory. The date of the comb is unknown but is listed in the museum's records as 19th-20th century.
10. A Meissen teapot with no known date, 19th century. The company, Meissen factory, typically manufactures porcelain objects designed by its employees. The name of the designer in this case is not known.
11. Same as 11, but the name of the designer is known and the designer's death date is 1945.
12. Same as 12 but the designer's death date is unknown.
13. Same as 11, 12, and 13, but in this case the designer is not an employee, but an independent designer contracted by Meissen for a special project.

Thanks in advance for any advice you may have  

William Real
Carnegie Museum of Art Received on Thu Apr 06 2006 - 08:30:00 GMT