The SR-75 Valkyrie II is for the most part still the same design as it was during FS5, it has been rebuilt a few times since then, but the overall design and layout of it is the same.  The original SR-75 was not supposed to be a direct copy of the Testors plastic model kit because there were a few things I didn't like on it (the main thing being the engine layout copied from a BAe Concorde) and because I just wanted to make something a bit different, sort of like a concept of a concept as silly as that may sound.

Another thing is I didn't want to treat the SR-75 as just an aircraft of the Aurora project, since in most of the eyewitness accounts the "aurora" are often referred to as the triangled craft, the "mothership" craft gets a little less press.  I am not too sure where the notion of a 2 aircraft project began from, but it has gained acceptance with the sightings of a few large white aircraft sightings of an aircraft said to be reminiscent of the old XB-70 bomber.  The SR-75 series will contain at least 4 variations including a test plane, and a spy plane, as well as the "mothership" type used in the Aurora Project. -- SR-75 Versions

Personally I don't know if either of these aircraft exist or not, but I haven't seen anything to make me believe they do, nor have I heard anything that makes me believe they don't.  An Air Force "denial" is about as good as a confirmation now days. I highly doubt that if they DO exist that they would look anything like this, and I am almost certain that they wouldn't be referred to as SR-75/XR-7.  I'd like to believe that there is something like the Aurora aircraft out there, the stories of it are quite remarkable, even though they seem to contradict each other from time to time.  I am just toying with the idea that there just may be something out there like this after all.  -- SR-75 Screenshot Gallery