As for credible witnesses, as you may recall, we do have a freeper (also a physician and decorated war hero) who actually held a small piece of the purple in color I-beam that his father brought home from the 1947 Roswell event, he may have been around 12 years old in 1947.
The above similarly shaped object was seen in the early 50's.
Two or three freepers also commented that they also saw a similar object, as recent as the mid 80's.
Thanks for the reminder, LVD! I personally know three credible witnesses myself who I met many years apart, but who described the same kind of craft, and saw it as far as I can tell in the same year (late '70s), one in So Cal at the time, and the other two up by Sacramento. Again, fool in paradise's insistence on "pictures or it didn't happen" is ... well, a fool's way of thinking! {^) Ironincally, in the book I mentioned, "Leap of Faith," written by one of the original Mercury 7 astronauts, had one prtty powerful anecdote about what happened to the pictures that were taken of something he saw!!! "Pics or it didn't happen .... " was exactly what the officials who made off with the pictures had in mind! Yeeeeesh!!!
Thank goodness I've never seen one of the things, but I know these three people well enough to know that they were telling the truth. And then, of course, there's Gordon Cooper. If he doesn't qualify as "credible," I don't know who would!