The observation deck at BWI
has the following on display;
A B737-200 nose section with viewable cockpit
A B737 vertical stabilizer
An entire wing of a 737 (minus the engine) with flaps and slats down, hanging from the ceiling.
A forward cowling from a JT9D, complete with fan blades
A main landing gear bogy from a 767
A fuselage section from a 737-200 showing the belly compartments and seat configuration, cut out in a fashion similar to the 747 pictured above.