Eric,
Here is a link. You enter "luger" into the search window to bring up the Lugers (photos and description and some history of each gun) in their collection :
http://www.museum.nps.gov/spar/wordsearch.htm
BTW...you might find this discussion topic over on Jan's Gun Boards an interesting read as well. It deals with one gun in the SA Museum collection and its importance to four 7-shot Lugers that have appeared in the USA.
http://luger.gunboards.com/topic.asp?TOPIC_ID=11236