I think there is more of a big market for detailed, feature-laden scale models of smaller steam locos. Maybe its just me, but the Legacy Atlantics and 0-8-0s and Premier 2-8-0s and 4-4-0s are some of my favorites - just fantastic locos. done right, they are little jewels of models and they will fit and run on a lot of layouts where the big boys, so too speak, never will: there is a big market. In particularly, there were a lot of interesting locos in that size range made in the three decades around the turn of the 19th-20th century, leading up to WW1. A manufacturer would probably have to put them out on the market and let word-of-mouth gradually spread about how appealing they were, but I think once that happened they would sell well and consistently for a long time.
Then again, I would love to see a Soviet AA20-1 4-14-4 steamer - you can never have to many drivers -- but then that probably is just me . . .
While I love my Big Boy and other BIG locos.....I find it harder to find nice smaller steam. I did just get a Lionel 2-8-0 that I will rework soon....but smaller steam would be good.
