You can find a 1:48 Mercury-Atlas at Surfduke's
http://www.mos95b.com/ - click on the "other projects" and follow the Mercury link - and a 1:96 Mercury Atlas at
Nielspapermodels - links about half way down in the archives section. Can't recall seeing a larger one.
Let's see, a 1:48 shuttle would be ...
absolutely insane! What are ye thinkin'?
Yogi