The Air Force Museum has a AQM-34N, one of the ultimate developments of the AQM-34 series. Its exterior shape is vastly different compared to the short-wing Firebees shown on this site. It seems it only shares the radome, inlet and vertical tail.
The identity of this Firebee was finally found on the museum website in 2010 by Craig Kaston (here), and it is serial number 67-21506. This fits in one of the 1967 serial blocks for Ryan BQM-34A Firebee drones, 67-21501 to 21700. The site reports that it was retired from active service in 1973. It looks sinister in its weathered black paint, which suggests it has flown several missions, or has been stored outdoors. At least six mission markings are applied to the left forward fuselage, and it appears that no identity is painted on. This identity would most likely have been an 'N-xx' number (the xxth built AQM-34N) instead of an Air Force serial number.
Mark Nankivil visited the museum in December 2003, and made the following walkaround photo series.