I think Vulcans were some of the most beautiful aircraft ever designed. Much better looking than Concorde.
As you probably know, a Vulcan was used for testing the Concorde engines. I Can't remember where it is, but I'm sure I've seen it.
I am not sure about the test bed story, but the Olympus engines share the same origin indeed.
EDIT:I have checked this in
Wiki now.
But, no, the most beautiful aircraft ever designed has to be a Mirage.
I am partial to the F1 version, but all of them, even the IV, look good.