I would just like to point out that the weedy fields, or forests, or rocky landscapes that border the railroad ARE indeed as historic as the railroad itself if not more so. However for purposes of the tourist ride they are important in context - what does the view look like?
If, as some proposals for the RVC have said, it is to be a modernist structure with no historical architectural styles used, I think it has failed in the context of its view from the railroad. Looking around, one would see some old buildings, old rail cars, old locomotives, and then - WHAT THE HECK IS THAT~!
I prefer a weed covered hillside to a Helmut Jahn interpretation of Steam Locomotivation.
If the building is built in context with D&RGW practice, or even as an old commercial building as would be seen in the region, it succeeds in its context. It is not historic, but it does not deter from the train ride. Making the connection for visitors to use the facility is a matter of proper signage and directing them to the front door. I like the idea of selling the train tickets there as well. Then they would have to be in the building a for at least a spell.