I found these photos from an exhibit at the National Army Museum in London on tumblr. According to the museum website the exhibit is running through October 31st and is free to enter, but you must reserve a ticket.
It was at a trade show. But like you said, the project never got off the ground. It was going to be a static display as far as I know. Not a working airsoft.
I was thinking about revisiting this project. I have a static version but I want to make a moving version. The problem is there isn’t an airsoft model close enough to mod that I’ve seen.