@ Timekeeper
Yes, yes, yes, yes!!!!
My head (and wallet) would explode! I love building fine scale models, mostly WWII in 1/48 scale and modern in 1/72 scale, and I would love this!
Snap together and pre-painted diecast for beginner, casual builders, more intricate plastic, photo-etched metal, resin kits for the more experienced builder.
N scale or HO train scale would be nice as well, and believe me, they would become instant collector items. Sell an entire line of attractions, people, characters in the same scales, it would be pretty awesome. People turn entire portions of their house into a railway, with towns, rural areas, farmland, so I could see some of the more Disney addicted doing that to their home, but recreating the parks, but with monorails... I'm going to have a fit.
And note on expense, some kits, especially with mixed media (plastic, resin, etc.) can get very costly. The more "fine" the detail, the greater the production cost as well as volume produced. They could make different "levels" for everyone.
Sorry for the long boring post, but I LOVE this idea!