Acetate should be available from either an art shop or a stationers, it's used for overhead projectors.
There are only two layers and basically the shiny blue card layer is first then the printed acetate is laid on top and a frame is made around the edges binding the two together.
Another option is to use double sided tape to stick the two layers together, you could either use a trim around the edge or cover the whole surface. It's probably best to stick them with tape first and then cut out the shapes.
I haven't got any photos of my international space station because it was made before digital cameras

And the original prints are in the attic somewhere (which isn't really an option).
I hope that makes more sense

cheers
James