They made 40 of these things? Where are they now?
One’s on loan to a British air museum. Wright-Patterson, of course. Smithsonian’s Dulles Annex. Probably a couple each at Langley and Edwards.
At air museums all over the country: March AFB in Riverside, plus several others already mentioned in this thread. You can walk right up to, and underneath, them, although I doubt any museums allow you to climb into the cockpit--March doesn't.