Amy,
Have your mechanic contact the Swift Museum Foundation - they are the repository of all things Swift, including information on the mods (Cessna 150 seats are a popular mod for Swifts).
http://swiftmuseumfoundation.org/I've dealt with the folks in the past and they've been incredibly helpful. I've gotten the feeling that they know where every mod and every part is in the country, including stuff hidden under some guy's sofa.
Hope you do get a ride - they are lovely flying airplanes but most definitely not swift if they have stock engines. Very draggy airframes. With big engine mods they are fast. One interesting design quirk/feature is that they are difficult to three-point land due to the sudden drag rise as the landing gear wells are exposed to the relative wind and the loss of effectiveness of the elevator/horizontal stabilizer as it nears the ground. They wheel land beautifully, however.
Warmest regards,
Rick