погляди тут..
http://www.sr-71.org/blackbird/index.htm

Б-эшек всего 2 штуки было построенно

мне кажется что 974 все-таки "А" был
по-крайней мере вот тут
http://www.blackbirds.net/sr71/sr-timeline/srtl60.html написано
16 Feb 1967 First flight of SR-71A #974, Lockheed Test Pilot/RSO: Bill Weaver/ Steven Belgau (LSW; BB)
13 Mar 1968
3rd SR-71A #974 arrives at Kadena AB, Okinawa, USAF Pilot/RSO: Robert Spencer/ Keith Branham (SME)
26 Jul 1968
SR-71A #974 with USAF Pilot/RSO: Tony Bevacqua/ crew, positively fired on by SA-2 missile, it was photographed by the SRs cameras (SME)
Sep 1968
Switched OL-8s SR-71s #974,#976,#978 with #962, #970, #980 (SME)
22 Jul 1987
Persian Gulf missions from Det 4; SR-71A #967; USAF Pilot/RSO: Smith/ Doug Soifer
9 Aug 1987: SR-71A #975
26 Oct 1987: SR-71A #967
30 Apr 1988: SR-71A #974 (BB)
974/ #2025
Lost on 21 April 1989 near the Phillipines in the South China Sea. While climbing out from Kadena AB, Okinawa, the right engine exploded severing the hydraulic lines for the flight controls. Seeing the lowering hydraulic pressure the USAF PIlot: Lt. Col. Dan House headed for the nearest base, which was in the Phillipines, nearing the coast they lost all control of the SR and he and his RSO: Maj. Blair Bozek ejected safely landing just off the coast of the Phillipines. They were rescued by native fisherman shortly before US Rescue forces arrived. The SR was recovered after a lengthy salvage mission.
http://www.blackbirds.net/sr71/index.html
так что и на Окинаве он тоже был =)

Это фотография обоих членов последнего экипажа House/Bozek



Удачи!