The Artist said:
I'm going to have to do some digging for the exact title, but I remember seeing either this mock up or a sound stage copy used in a low grade sci-fi film. I want to say that it was called "X - The Man With X-Ray Eyes"
The main character develops the ability to see through things so he is recruited into a government agency then sent behind the iron curtain. While being extracted, his contact led him to a tarp covered shape which was revealed to be this aircraft when they dragged away the tarps. You saw them climb into the thing then they cut to cheesy animation for the flying sequence.
I saw this movie only once or twice back in the late 60s or early 70s.
Mike
Update:
I've checked IMDB and Wikipedia for information on this title and what I've found does not suggest that this is the right film. I'm still fairly sure that the letter X was somewhere in the title and that's how I ended up watching Man With X-Ray Eyes - I thought it was going to be that other movie. I'll keep looking because some additional footage of this mock up would be cool to find.
I believe I've identified the movie but it may take a bit to confirm this as the movie is not currently available.
"Project X" Directed by William Castle and released in
1968.
Don't confuse it for the later movie about chimpanzee pilots.
You can find the IMDB page here
www.imdb.com/title/tt0063465/
I knew it had something to do with scientists and an agent going behind enemy lines.
I'll keep looking to see if I can find anything else from this movie.
Mike