A video where some guys get into the archives of the US Space & Rocket Center in Huntsville, Alabama. On display is a sizable (looks like about 1/50 scale) Space Shuttle, ET and Boosters made from plexiglas. It is a thing of beauty, surely a chore and a half for the model shop back in the day. This is *not* the final Shuttle design; some differences are obvious such as the split cargo bay doors and, while unmentioned in the video, the existence of extended OMS pod fairings, reaching out onto the aft of the cargo bay doors.
Last time I visited the USS&RC in something like 2005 they had a much bigger plexiglas STS model on public display, something like 1/10 scale, along with a gigantic plexiglas Saturn V. Such things are fantastic artifacts, and if you are working on a complex engineering project like this a see-through plexiglass large scale model is terribly helpful. I suspect that such things are only rarely made these days, as computer graphics are a lot easier, cheaper and more readily updatable. But nothing beats a Real Thing. And at least so far, 3D printing is not up to the job of stamping out large-scale transparent models like this. But someday…