I believe the most general term applied to artistic endeavours, which would seem appropriate given the nature of the piece.

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Note added at 2002-05-12 21:09:55 (GMT)
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Isn\'t \"installation\" referring to a single piece here? In English, it may be used for a collection, not just for a single piece.

This is meant as agreement with ttagir above, but my comment is too long to fit in the box. See the reference below, in which we read (emphasis added):

"In celebration of Winterthur's 50th anniversary, a selection of the rarest and most renowned objects from its collection of American decorative arts will be on view in the first exhibition of its kind in the museum's history. Winterthur, an American country estate known for its museum, garden, and library and located in Delaware's picturesque Brandywine Valley, opened to the public in 1951 to display Henry Francis du Pont's (1880-1969) magnificent collection of American antiques. This INSTALLATION will feature some 300 masterpieces from Winterthur's collection of 85,000 objects, including furniture, textiles, paintings, prints, ceramics, glass, needlework, and metalwork, all made or used in America between 1640 and 1860. The exhibition will also include photomurals of the museum's famed period rooms.