You posted the SR-71, don't worry, you had it correct. The SR-71 is a slight variation of the A-12 and would not have been possible without the A-12 already being in service; Lockheed developed the A-12 for the CIA and it was already in flying when the USAF came knocking and wanted a replacement for the U-2. Lockheed had to get special permission to even reveal the A-12 existed. The A-12 was then revised to meet USAF requirements and renamed the SR-17. When the funding was sent to Congress for approval, someone got the name wrong and typed "SR-71" - due to the challenges of funding a black project, it was easier to rename the aircraft than it was to fix the paperwork.Fair point! The almost-the-same SR-71's design is clearly A-12-based, and that was earlier. A great point that it was even more ahead-of-it's time.
Am I mistaken that the image I used, though, was the SR-71 and not the A-12? I know the differences are subtle, but the SR-71 is a 2-person crew, and believe it entered service in 1966.