Last summer, I found and purchased the 1/144 scale Fastway Mars Liner model kit by Glencoe Models. Keen Disneyphiles will immediately recognize the rocket as the TWA Moonliner. Due to licensing issues, the name had to be changed, but there is a clever way around that.
Glencoe Models finds and resurrects classic model kits that have been “long abandoned by their original companies.” They don’t have a huge selection, and as far as I can tell, they don’t sell directly to the public. But, that’s where online stores come in. I bought the Glencoe Models MARS LINER spacecraft 1/144 scale model kit on Amazon for about $20 (including shipping), which was a steal. But, there were many hidden . . . surprises.